While searching in The City recently for the site of the hall of Gerard the Giant, see previous post, I noticed a small park the other side of Queen Victoria Street.
I investigated, found it to be Cleary Park, noticed that the top of it was apparently right above the Circle Line, behind a big wall, and the park then was double terraced steeply down toward the Thames.
After walking down the stairs to the bottom of the 3 terraces I noticed with excitement that several of the walls were clearly medieval, one mainly from the brickwork and another, on Huggin Lane by it’s use of rubble and old brick. I had discovered, as Columbus discovered America, what Vic Keegan has called ” … surely the biggest hidden gem in London – Huggin Hill Roman Baths. ”
Keegan continues “They were saved and excavated in the 1960s amid considerable publicity and controversy, but have since faded from public consciousness and almost entirely from public vision…Most of the extensive remains of the bath house are buried under office blocks at either side of Huggin Hill at the bottom of the slope. They have been preserved, but only after being filled in. Some of the walls were three metres high. There is no public access. Had they been discovered today, maybe the Bloomberg factor would have meant new buildings being constructed to allow it.” 
After reading up on the area later this I could see several sources, including Historic England state that some Roman walls can be seen above ground but I have to say all I could see were what I believe to be medieval walls from their brickwork.
“The monument includes a Roman bath house surviving as upstanding and below-ground remains. It is situated on a south facing slope of London Clay and gravel near the north bank of the River Thames. The remains extend to the east and west of the lower end of Huggin Hill, immediately north of Upper Thames Street, and on the west side of Little Trinity Lane. A section of the north retaining wall of the bath house and walling of a medieval undercroft survives in Cleary Gardens. However the site is otherwise preserved as buried remains below modern buildings and Huggin Hill roadway.” 
Excavations show the area had a very large and thought to be public bath house and dated to the 1 and 2nd centuries AD .. “There were numerous bath-houses intended for daily use, for example, public ones on Cheapside and Huggin Hill, dating to the late first or early second century;” 
But oddly the baths appears to have been “systematically demolished” in the 2ndC.
“The Roman public bath building was identified in 1964. It was situated on either side of the lower end of Huggin Hill in the west of the City. The baths were clearly located on a spring line as it was the small private bath house at Billingsgate in the east of the City. Huggin Hill was a double public bath with a series of separate bath rooms as seen at Leicester and Wroxeter. Thus, with its size, enormous by provincial standards, its prominent position and its separate large bathing rooms for men and women the complex must have been a prestige building. This is further corroborated by the location of the Huggin Hill baths as they were located on the waterfront in a district where there is some evidence of other ‘public’ constructions such as temples, suggesting that it was an area used for public gatherings and possibly entertainment. With so much expense lavished on the building, it is difficult to understand why the Huggin Hill baths were systematically demolished as early as the second half of the second century and the hillside was restored to its former sloping profile. The destruction of the baths was clearly not undertaken for the purpose of replacing it with another public building, since the fragmentary traces of later Roman stone buildings on the site show no re-use of building materials from the baths.” 
Anyway a lovely little example of ancient London that you occasionally find! And to think that under there and the surrounding buildings much of the baths still exists. How much more of the City is like that?
Btw the park is called Cleary Gardens and if you need a quiet sanctuary while in that part of the City, go there! 
It’s just a short walk from Mansion House Tube Station in between Queen Victoria Street and Upper Thames Street.