4 Pics 1 Word Level 1852

Answer:
Curved
Hint
What is the answer to the 4 Pics 1 Word level with A wooden staircase, A large curved white building with yellow lights, Railway track, and A track in a park?

Hint
What is the answer to the 4 Pics 1 Word level with A wooden staircase, A large curved white building with yellow lights, Railway track, and A track in a park?