Some of the famous echo chambers were like the ones at Capitol Records, built way down under ground in the form of concrete bunkers.
The other options that came a little later were plate reverbs, made from huge sheets of metal, similar in principal to the spring reverb...and of course, simply recording in various larger spaces that had good reverberation, though you couldn't always just move a recording session into a nice cathedral or hall.
Those are the reverb sounds of the '60s and early '70s..and then came the analog and digital electronic reverbs.
I like the flavor of plate reverbs, and I use a couple of digital plate reverb settings that I have in my racked reverb boxes for a lot of my vocal tracks.