I sometime see juniper trees at temples in Kamakura. There is a variety of types of juniper, but it is Chinese Juniper that you see at temples in Kamakura, which is thick stem and tall.
Regarding a juniper tree, Kencho-ji is famous for it. I tried to see which temple has a juniper tree. According to the WEB page of Kamakura City, juniper trees of Kencho-ji, Engaku-ji, Jochi-ji, Jufuku-ji, Daikei-ji, Seifuku-ji, Jokomyo-ji, and Tsurugaoka-Hachiman-gu have been designated as a natural monument.
At Kencho-ji, some juniper trees are planted in front of Butsu-den. According to the WEB page of Kamakura City, it is eight trees. Since I don't remember well, I will count it when I go next time. The largest tree is 13m height, 6.5m around of stem, and 730 years old (estimated). It's really big. It is said that Rankei Douryu who is founder of Kencho-ji has planted them by himself.
In Engaku-ji, there is juniper tree at Hojo. The tree also has planted by Mugaku Sogen who is founder of Engaku-ji. It may be more than 700 years old.
Jochi-ji has three juniper trees. I don't remember well, I will confirm it when next visit. A Picture below shows one of them, which planted beside of Honden, which is very tall.
In Jufuku-ji, I remember big juniper tree which planted in front of Butsuden.
I never been to Daikei-ji, and I missed juniper tree in Seijuji-ji and Jokomyo-ji. I will try to see next time.