On the instruction of Henry Arthur Herbert (the eponymous HAH so prevalent on various Muckross structures), Tower Lodge was built as a sportman's lodge in 1837 for the rather modest cost of £200. Allowing for inflation and all that other stuff, we have about €30,000 in today's money. Sounds like he got a bargain.
It was described as being "built for the accommodation of gentlemen who visit the Upper Lake", shooting and fishing being the pursuits of the gentlemanly class. The lodge tower would have provided a vantage point for shooting deer, and probably anything else that moved, as well as being ornamental in appearance. Comparing then and now from the photo, the vista was much clearer and vegetation far less dense. In later years employees of the estate lived in the lodge with their families. It was occupied as a residence until the early 1980's and has been vacant since.
Examining the background photo more closely, the lodge has the look of a rather surprised face. Hard to unsee afterwards.....
The inside of Tower Lodge itself is not accessible and there is a review ongoing (for years) to refurbish it, but it can be easily viewed up close from the woodland. For safety sake when visiting the tower, don't attempt to walk along the road, but rather go through the wood from the parking spot. It is no more than a minutes walk.
Park with care - there is room for 1-2 cars, but the road is narrow and winding so due consideration is required. Note too that mobile reception is pretty much non-existent.