some of these tanks are pretty cool. i enjoyed the early 1900 ones. i thought the thread would be oldest as in the longest running tanks (not being shut down for any significant time). that'd be a cool thread too
Here are some pictures of a friends tank. It was originally built in the very early 1900's and was in the Steinhart Aquarium in San Francisco. Interior dimensions are 120" x 24" x 24". I restored it for him over the course of two months. He has some older ones set up also from the 1800's, but I don't have pics of those. He is a VERY avid collector of antique aquariums.
My 240 was custom made in 1978 for my neighbor and has been in continuous use ever since, with the exception of 1 week during the move from his house next door to mine.