What is the significance of a Samadhi place of a Saint? Is there any special power or energy around that place?
As said by Sai in comment, its powerful place. Any rituals/sadhana done near samadhi yields several multiples of actual benefit of the act. Its best place to practice meditation & yoga. Service to samadhi may be considered as service to Guru. Guru is form of God, his adobe is kailsh/vikunta hence its equal important place to worship like other kshetras.