It took a bit of hunting to figure out what was the subject of these photos. I assumed that it had to have been a tourist spot in either Korea or Japan, so at first I looked for images of parks in either place. I then tried looking up architecture for Korea and noticed the roof line on my photo and the roofline on the images online began to match.
My first thought was that it could be the Kyŏngbok Palace but on close examination the number of windows across the front of the building didn’t match and the fencing that surrounded the building didn’t exist on my photo. There were several palaces in Korea and they all seemed to be built with the same basic design. I then did a search on Korean palaces and went through several dozen photos before I found the one that matched. Changdeokgung or Changdeok Palace is set in a large park setting in Jongno-gu, Seoul, South Korea.
Dad must have really enjoyed visiting the palace as he took several pictures of what he saw. The structures on the palace grounds are set within the treed landscape, each building peaking out from behind large trees and reflected in ponds.
The original construction of the palace started in 1405 and was completed in 1412. The palace was destroyed and rebuilt after the Japanese invasion of 1592 and an arson in 1623. The last emperor to live in the palace was Emperor Sunjong who lived there until his death in 1926. Each time the structures were rebuilt they followed the original design.
One of the buildings on the palace grounds that dad took a photo of was the pavilion Buyong-jeon in the secret garden Biwon. There are photos on line of this same building and it seems to be still exactly the same as it was in 1953.
For future reference, I marked on each of the slides the location, just as dad had done with some of the other slides.