To the east of the valley is the coastal ridge and small community of Bulgo, also the name of a hill in the area and the former name of Otford.

The town is on the southern tip of the Royal National Park and features many native plants in its bushland like the Dendrobium Lilly.

Trains on the line stopped at Otford to take in water and a small railway and sawmill centre developed at the entrance to the tunnel.

A timber mill at Karingal, Lilyvale, in the north of the Otford valley was established by Thomas Gergos and his three brothers in 1875.

[2] The current railway tunnel between Otford and Stanwell Park was made in 1917 after annoyances in the old one such as buildup of smoke in the unventilated route and the steep descent.

The abandoned, original railway tunnel between Otford and Stanwell Park was used for a mushroom farm but is now disused.

[1] Otford has little remaining services but retains a public primary school, railway station on the NSW TrainLink South Coast Line, a volunteer Rural Fire Brigade, Otford Community Hall, tennis court and playground and a cafe.

Otford railway station, once had award-winning gardens and picturesque buildings but is now a stark concrete and brick commuter stop.