The Radio Kaikan is the iconic building opposite the JR Akihabara Station. It was the first high-rise building in Akihabara in 1962 and was horribly derelict by the 2000s (It was horrible, I have pics somewhere). It was rebuilt from 2011 to 2015.
It's where the time machine crashed in Steins;Gate, and is now being destroyed in 16 Bit Sensation.