Borderlands custom map links
Here’s all the individual custom map links I can find for Borderlands 1.
Most of them come with instructions on how to put the files in the right place but ask if it's not clear.
Note that if you exit most of these maps part way through, you'll have to start the mission again from the beginning.
You need the Oasis map hub to use all of these (see Mapslot 6 in list below).
Note that because I wanted to keep this list 'clean' I've included working links to mapslots with useable content only
EDIT: I recently (Nov '15) realised it's still possible to access the old forums, so you can actually find the complete list of map hubs, links and importantly discussion about how far these projects got, here: some of the links are broken though whereas all the links i have listed separately in my post below are working: http://oldforums.gearboxsoftware.com/oldforums/20150308085538/http://oldforums.gearboxsoftware.com/showthread.php?t=108800
Prior to discovering the above old forum link, I put up a companion post to this which just for the record lists all of the custom map projects, including those with no working link or which were unfinished. I'll leave it up in case the old forums go down again: http://forums.gearboxsoftware.com/t/borderlands-1-original-list-of-mapslots-reservations-etc-no-links/527314
Hope this is helpful - do ask me to add any more maps you have or any updated map versions - keep B1 alive!
Complete Download: xDORSx, another forum user, has kindly created a map pack with everything in it as one download - This includes some maps i don't have individual links for, so if you're starting from scratch this is probably a good bet...: http://steamcommunity.com/sharedfiles/filedetails/?id=507827284
I'll still keep this list of individual links going though, and if anyone wants to give individual links for ones where it's in a pack or have updates etc do let me have them
Sources of several maps
Some of the maps are amalgamated at common sites:
this is a download, again courtesy of xDORSx, for seven mapslots for which i couldn't find individual links: MS5 - Secret hideout of crazy Psychos; MS11 - Zombie Skirmish ('unofficial' map for this slot); MS13 - Yuki-onna's Caldera Outpost; MS15 - Boss Junction; MS18 - Abandoned Base - Zombie Infestation (note i couldn't get this to work); MS19 - Fifth Column; MS24 - Dead Hill; https://drive.google.com/file/d/0B9Ws0xX48rdjVGp3Y2VVVE5mMFk/view
Nexus Mods Borderlands Map Link: http://www.nexusmods.com/borderlands/mods/searchresults/?src_cat=3
Gamebanana Borderlands Map Link: http://borderlands.gamebanana.com/maps
Gitface's maps - Valley of Death (slot9), Maze of living dead (slot17), and Doomdocks (slot26) - are here: http://forums.gearboxsoftware.com/t/gitface191s-home-made-maps/88751
Individual Links with Oasis Mapslots:
Crow’s Nest (Mapslot 2) – good challenging map where you fight some intense battles to reach some loot: http://www.mediafire.com/download/3c777nvcus63rsu/Borderlands+-+Crows+Nest.7z
Secret Hideout of Crazy Psychos (Mapslot 5) - part of the seven-map pack: https://drive.google.com/file/d/0B9Ws0xX48rdjbUFLRm5SZWRhXzg/view
Oasis Full DLC fasttravel hub (Mapslot 6) – you need this to run all the custom maps - it also enables fast travel around the official DLCs - General Knoxx, Claptrap Revolution and Zombie Island of Doctor Ned: http://s6fulldlcfasttravels.googlecode.com/files/FullDLCFastTravelHUB.rar You can also download it from here: http://www.nexusmods.com/borderlands/mods/searchresults/?src_cat=3
Abandoned Badlands (Mapslot 7) fairly large map with some new bosses - you're given three difficulty levels but unless you've got some very good weapons you might want to start with the lowest!: http://theabandonedbadlands.googlecode.com/files/ABLBetaV1.2.rar
Valley of Death (Mapslot 9): really excellent long map which is designed to be played through twice. Completing it the first time opens a few portals to travel around and the enemies are swapped and a lot more doors opened to make a second playthrough shorter but with more loot possibilities. Note that if it doesn’t seem right the first time you play it just exit the game and try again – it worked for me… https://sites.google.com/site/gitrmanuk/home/valley-of-death Another link to it is here: http://www.nexusmods.com/borderlands/mods/3/? Or there is a third link to the map here: http://borderlands.gamebanana.com/maps/160909
Skag Mountain (Mapslot 10) - good short playable map but unfinished: http://www.mediafire.com/download/rv1uvemastw4b5r/mapslot10.umap
Zombie Skirmish (Mapslot 11) - an 'unofficial' map (ie the slot was originally reserved for something else. Consists of a large valley with various zombie-related enemies - at least in BL2.5, it's an endless battle and i haven't found a point to it yet... part of the seven-map pack: https://drive.google.com/file/d/0B9Ws0xX48rdjbUFLRm5SZWRhXzg/view
Eridian DLC (Mapslot 12) – good map which was the start of a larger, and sadly unfinished, project - the idea was an initial short map which then leads to links to areas owned by the different gun manufacturers. From memory it said on the old forums that ratrace had completed two of them - Vladof and another - but i can't get through Vladof because of what seems like a glitch (I got stuck at the lift in the Lance base) but it's still worth playing - there's a good amount of playing time and you even get to ride on a rakk! : http://www.mediafire.com/download/a74ju3p6rbt05os/EDLC+BETA+1.5.rar
Yuki-onna's Caldera Outpost (Mapslot 13) - small map and not nearly finished - not a lot happens. Part of the seven-map pack: https://drive.google.com/file/d/0B9Ws0xX48rdjbUFLRm5SZWRhXzg/view
Lone Creek (Mapslot 14) - good map but buggy and I couldn’t get all the way through: http://www.mediafire.com/download/02456azz4bp310y/Lone_Creek_Beta_v1.15b.rar
Boss Junction - map with a few arenas where you fight bosses! - part of the seven-map pack: https://drive.google.com/file/d/0B9Ws0xX48rdjbUFLRm5SZWRhXzg/view
Braindead (Mapslot 16) – good straight-through shoot-up map with zombies, skag and scythid: http://www.nexusmods.com/borderlands/mods/5/?
Maze of the Living Dead (Mapslot 17) - Like it says on the tin, this is a maze with lots of living dead in it
i'm not sure if there's another way out - i think you just go around and open all the chests then head back to the entrance... – http://borderlands.gamebanana.com/maps/161901 or another link is here: https://sites.google.com/site/gitrmanuk/home/maze-of-the-living-dead
Abandoned Base: Zombie Infestation (Mapslot 18). note setup doesn’t work in Windows 8.1 so I've not been able to get this one going yet - let me know if you can help! https://code.google.com/p/asptabzi/downloads/list - is also in the seven-map pack but i can;t get it working there either... https://drive.google.com/file/d/0B9Ws0xX48rdjbUFLRm5SZWRhXzg/view
Fifth Column (Mapslot 19) - a decent map with missions to beat various bosses - warning though - it's hard in BL2.5, as a few of these maps are, because the enemies just keep spawning... i couldn't get it working with the following link as i have Windows 8.1 but this link is ok if you have an older version i think http://the-fifth-column.googlecode.com/files/AspTfc_Setup_v2.rar - BUT it does work if you download the seven-map pack: https://drive.google.com/file/d/0B9Ws0xX48rdjbUFLRm5SZWRhXzg/view
Abandoned Base (Mapslot 20) - multiplayer only: https://code.google.com/p/abandonedbase/wiki/wikiabandonedbase
Research Space Station (Mapslot 21) - intense mission where you have to fight your way through a LOT of scythid to destroy a space station and escape - well put together and good fun: https://code.google.com/p/borderlands-spaceport-hub/downloads/detail?name=Spaceport_v1.0.rar&can=2&q=
Craw Hill (Mapslot 22) – another Crawmerax farming map: http://www.mediafire.com/download/48j4y9sdb05t6w9/Mapslot22.umap
Dead Hill(Mapslot 24) - fairly good zombie map but has endless enemies respawning - part of the seven-map pack: https://drive.google.com/file/d/0B9Ws0xX48rdjbUFLRm5SZWRhXzg/view
Forum Fighters (Mapslot 25) - Intense arena battle against a lot of enemies - http://www.mediafire.com/download/p3djsw2onddjlz3/forum+fighters1.5.rar
Unhallowed (Mapslot 27) - small map in a courtyard with 3 chests and a lot of zombies who don't want you to open them!: http://borderlands.gamebanana.com/maps/160901
Choking Grounds (Mapslot 30) - nice badlands-style map, not finished (the missions stop after Scooter) but still good to explore and with a couple of heavy battles: https://www.dropbox.com/s/ol4vceawq666q9a/The%20Choking%20Grounds.rar?dl=0
Shin-O’s DLC (Mapslot 32) – some good maps with intense battles which are very challenging in places - gives out good weapons and shields: http://www.mediafire.com/download/dqdjdsbdf23697h/Shin-%C3%95%27s+DLC.7z
Underdome 2.0 (Mapslot 35) – really good extra maps in a restyled Mad Moxxi’s underdome – better than the original and gives out fantastic special ‘Moxxi’ weapons! - now on version 4: http://www.mediafire.com/download/5g81fmxzl91cz1v/Arena+R4.rar You can also follow progress on this map on this forum here: http://forums.gearboxsoftware.com/t/the-underdome-2-0/10389
Craw Farming Map (Mapslot 38) – Crawmerax farming map: http://www.mediafire.com/download/i5sb9van2vvtjwq/5Craw+Farming+map.umap
Tiny Snowmap by Yeticavern (Mapslot 40) - very small map which gives you a new weapon - 'The Yeti' - and some lance to test it on - http://www.mediafire.com/download/oebwagyz7cakv2m/mostawesomemap.rar
The Cube (Mapslot 41) – really excellent map – very challenging and brilliantly put together: http://www.mediafire.com/download/u4ug24vd4a684ec/Mapslot41.umap
Fun City (Mapslot 45) - promising but unfinished map which does feature one big battle against a variety of enemies: http://borderlands.gamebanana.com/maps/download/159866