If you felt like the independant orginizations of Skyrim had to little influence of its landscape then this mod is for you. When it is complete there will be new hideouts for every you can join plus more. 

What this mod adds 
-Four Thieves Guild Hideouts each with their own secret entrances and exits on the inside and outside of the cities of Markarth, Solitude, Whiterun, and Windhelm. Each hideout has follower thieves and new fences. 
-Five Dark Brotherhood Sanctuaries in Markarth, Riften, Solitude, Whiterun, and Windhelm which can also double as player homes. 

Locations 
-Thieves Guild 
Markarth-Right outside the warrens entrance 
Solitude-Beekat's Tower on top of the front gate. 
Whiterun-Inside the wall near the front gate. 
Windhelm-Argnar's House in the alley leading to the gray quarter. 
Master Key-Mercer's desk in the cistern. 
-Dark Brotherhood 
Markarth-On the upper walkway between Understone Keep and Nepos' House 
Riften-In the canals near the ratway entrance. 
Solitude-On the wall near the temple of the divines take the ladder down and the door is in the wall. 
Whiterun-Behind a tombstone in the cemetary at outside the hall of the dead. 
Windhelm-Behind the House of Clan Shatter-Shield. 
Master Key-On the table just inside the entrance to the sanctuary. 

This mod requires no other mods or DLC. If you have any suggestions or bugs to report let me know in the comments.