Coming from Christchurch, New Zealand, known as 'the Garden City', I have to admit that, comparatively speaking, Japanese parks are downright ugly. However, religious and cultural monuments are equally, if not, more gorgeous. In my experience, from my many times here in Japan, the very best gardens and parks in this country (with the least foot traffic) are located at the temples and shrines. The castles are also beautiful, however, people are always wandering around.
Karate-do and Japanese religion: Another point worth mentioning is karate's particularly strong connection to Japanese Shinto. Most of the major Shotokan karate organisations (JKA, JKS, SKIF and others) here in Japan bow to the dojo 'kamidana', before and after practice. It is essentially worshiping the 'karate god's'. This is coupled with mokuso (meditation), which is connected directly to Zen-Buddhism. Even so, I've been told by Japanese seniors that outdoor training at jinja (Shinto shrines) is more meaningful for karatedo practitioners.
I wish you the very best in your karate training.