The key building is Evans Hall, a large, brutalist croncrete thing that is slated to be demolished & replaced for earthquake concerns.
https://en.wikipedia.org/wiki/Evans_Hall_(UC_Berkeley)
ARPANET was connected to the Ingres PDP-11/45 (or 11/70?) in Cory Hall
Ing70 via a VDH interface to LBL was rather late in the ARPANET history.
UCB was supposed to have its own connection earlier, but for reasons I never knew, it did not happen. I understand that it was targeted to be installed in the computer center, and UCB politics somehow waylayed it. When the Ingres contract was let, the Ingres team got the VDH connection as a part of it. No other systems could connect to the ARPANET. As Erik mentioned, in '78 Eric Schimdt's MS thesis work was developing the RS-232C 9600 baud "Berk-Net" for three machines -- 2 in Evan and then a wire in the steam tunnel that Bob Kridle pulled allowed them to connect the Cory Hall70, which was the "student" system that was were the primary work for 1BSD and 2BSD occurred (ex/csh et al.). Bob later ran a serial line up the stairwells of Cory and picked up the Ingres and the first CAD machine. Kurt Shoens, who was the primary UCB Mail author, hacked the Berknet support into his work. One of his primary additions was removing the "delivery" part of the mail into a separate program - that he called "delivermail."
Eric Alman was the system administrator of Ing70, so Eric hacked delivermail to pass email to and from the Berknet to the ARPANET. All was good until Ernie covax showed up and was connected to the UUCP net ;-)
Eric refers to that time as "the email format of the week" and sendmail was created to allow him to more easily handle the different formats. By then there was the DARPA 733/822 format (user@host), Berknet (host:user), UUCP (host1!host2...!hostn!user) being sources at UCB, as well as crap showing up from the IBM Educational System, CSNET and various other places trying be exchanged.
The CS department (College of Letters & Science) offices were on the 5th floor.
Ah .. but CS was a division of EECS -- very interesting history about that. The EE Dept was considered top three in the country and #1 by many ratings. They already had a huge history of working with industry and had created the Industrial Laison Office (ILO - which was how the UNIX BSD tapes were distributed until the creation of CSRG and a factoid. The ILO folks advised Fabry on how to run CSRG)). When CS was created, it was forked from the Math Dept. But, the Regents felt that if the CS was to have a chance to become a top 10 program, it needed to be put under the auspices of the EE Dept like MIT was -- and was attached to EE -- hence EECS.
The main campus computer center was in the basement, but they charged by the CPU/second, so only classes used those systems - in my day (1980-1983), the computer center had a CDC 6400 and six or seven DEC PDP-11/70s.
I could be wrong - but ISTR, there was an IBM 360/370 system down there also.
The 70s were used to teach CS courses such as the one I taught -- I think Bart Miller, Mike Carey and I taught CS-40 a qtr or two after Erik was an undergrad.
BerkNet (RS-232c long haul lines) connected the PDP-11s
Actually, not at all, which was all the more amazing. There were just CAT3 twisted pair with no conditioning. When we had an electrical storm, it was not usually to have the replace the 488/489 transcievers in the DHs or DZs. Kridle got pretty adept and putting machines sockets into the boards and he kept a box of chips in his office.
, and later the VAXen, though Ethernet supplanted it.
It was initially with 3Mbit Xerox boards. We were a little itchy about that, so Bob got an optical coupler/repeater (I assume from Xerox, but I don't know) in Cory's CAD machine room. The 10M stuff came about two years later, originally 3COM equipment with. There was a LAN in the Ingres machine room, another in the CAD, and another in CSRG's in Evans. The UCB CAD machine was on all three networks as it was in the middle. That is why Sam wrote the original routed stuff -- based on things he had seen at PARC for PUP.