the nearest hotel is in pelling which is around 4-5kms from here..

I do not think its a good ides to visit Sikkim in July. July is probably the wettest month in Sikkim. In July many times roads are closed due to landslides. Instead of July try to visit in October that is immediately after Monsoon.

Rabdentse was the second capital of the former kingdom of Sikkim from 1670 to 1814. The capital city was destroyed by the invading Gurkha army and only the ruins of the palace and the chortens are seen here now. However, the ruins of this city are seen close to Pelling and in West Sikkim district in the Northeastern Indian state of present-day Sikkim; Pemayangtse Monastery is one of the oldest monasteries in Sikkim which is close to the ruins. From the vantage point of this former capital, superb views of the Khanchendzonga ranges can be witnessed. This monument has been declared as of national importance by the Archaeological Survey of India. It was first established in 1670 by Chadok Namgyal son of Phuntsog Namgyal by shifting from the first capital of Yuksom that was consecrated in 1642. Regards Srikrishnan

From Pelling it should not be too long. We finished it and a monastery over an afternoon. It's about 45 minute walk from the road. About half an hour to another 45 minutes at the ruins should be good unless you want more time. The view is beautiful if the sky is clear. If you are interested in history or architecture-archaeology, then about 2 hours at the ruins. It is well developed with seats to sit quietly by yourself for some time. Good angles for pictures and panorama.