Bangalore to Mahabalipuram by road is about 330km. This is an ideal weekend getaway destination from Bangalore. The bonus is you'll be driving through Kancheepuram , The temple town with rich heritage. There is even a possibility of doing it as a circular trip back to Bangalore after visiting Pondicherry , which is about 100km south of Mahabalipuram.
Talking about the route, you can select one of the two routes from Bangalore towards Mahabalipuram. The first is via Chittoor in Andhrapradesh (take NH4) and the second is via Krishnagiri (take NH7 and NH46).
Route A (Mahabalipuram from Bangalore via Chittoor ) : Bangalore -- 66km -- Kolar-- 106km -- Chittoor-- 48km -- Wallajah -- 40km -- Kanchipuram -- 38km -- Chengalpattu -- 12km -- Thirukkazhukundram --17km -- Mahabalipuram
Route B ( Mahabalipuram from Bangalore via Krishnagiri) : Bangalore -- 40km -- Hosur-- 50km -- Krishnagiri-- 150km -- Wallajah -- 40km -- Kanchipuram -- 38km -- Chengalpattu -- 12km -- Thirukkazhukundram --17km -- Mahabalipuram
Talking of trains, travel from Bangalore to Chennai by one of those trains, buses or even by flight. Chennai to Mahabalipuram is about 50km. There are frequent bus services from the Koyambedu bus stand to Mahabalipuram, else a taxi would cost about Rs1700 including the waiting charges.
A milestone in Tamil language on the ECR showing distances to Pondicherry (101 km) and Mahabalipuram (5km)
See Also : Bangalore to Mahabalipuram
Here is the list of best 16 temples in Karnataka