Raigad is roughly 170 km south of Mumbai by road and 130 km west of Pune, both reachable in 4–5 hours along the NH66 and the Mumbai-Goa highway. The nearest railway station of any size is Mahad, about 25 km away, but most travellers come on day trips by car or organised bus.
Public transport from Mumbai is awkward — buses go to Mahad, after which a local jeep or taxi is needed up to the base of the fort. Hiring a car for the day from Mumbai or Pune is far easier and lets you stop for views along the way.