As Gaya is not only a pilgrim place but also famous for the sightseeing and Barabar is one of it.
Barabar is situated in the district of Gaya and it is 25 Km away from the Gaya city, it is accessible from the Gaya or from the Patan which will be 50km, there is a train halt in Barabar where the passenger train use to Halt for a min.
The best time to visit Barabar is Rainy day when everything looks green and the lord Shiva temple is situated above the Barabar mountain which is 3 above the ground level.
As it is out of the Gaya city so there are no Hotels available but you can easily get hotel in Gaya city. In terms of safety I am bit uncomfortable to take any vouch because there are no Police station nor security agencies.