Ok I can add comments here. The overall park is very nice and actually it can be moving. There is a part on the East gate, (from the map is that leg going on the right at the top of the park), where is located the jail, pretty desert and moving. Nearby you can find the tunnel ( 400 mtrs long) that bring you to the execution area and on the other side of the park. No problem for claustrophobic, but it's just long and kept in a low light to put you in the mood of the execution field. This one it self is just a small part of garden with a monument. Coming back just turn right in the tunnel again (you can only exit from the field using it) and follow it. It is quite long again but it will finish open air in another part of the park.

Another section, looks like the Vietnam Veteran memorial in Washington DC.

It with a visit. Close by there it the LongHua temple, also nice.