Map of campus can be found here
Map of union rooms can be found here
The Junior Common Room (JCR) is number 20 on the map; the entrance is opposite building number 15.
The Union Dining Hall (UDH) and the two Activity Spaces (UAS1 and UAS2) are located on the 1st floor of the Imperial College Union building (number 2 on the map), located in Beit Quad. The Union Concert Hall (UCH) is on the 2nd floor.
The Electrical & Electronic Engineering (EEE) building is number 16 on the map.