kb98 and I have just come back from a great trip to Bath, where our visit to the Roman Baths was a definite highlight, particularly as the Black Horse PCs and the Juma Gang both had to prevent a murder at the Hippocampus Baths in Parsantium! 

Here are some photos I took of the baths. The first one depicts the main bathing pool, which is heated by a naturally occurring hot spring and would have been covered in Roman times. The second picture shows mosaics of hippocampi.


 

The dark pool is the frigidarium (cold water pool) and the last picture shows the area under the floors. In the Golden Scimitars adventure, the PCs battled assassins in the hot and cramped  hypocaust underneath the baths' floors – an area similar to this but with a bit more room to manoeuvre between the pillars.