Baths of Caracalla
The Baths of Caracalla are absolutely huge. Apparently 1500 Romans could all bathe at the same time. It’s a bit like a modern indoor swimming pool, but more complicated. The baths were kept at different temparatures including the caldarium (hot bath), the tepidarium (warm bath) and the frigidarium (cold bath). You can begin to see how many English words derive from Latin (just think “scald”, “tepid” and “frigid”).