Wattsville is a small village in the Sirhowy Valley, eight miles north west of Newport, built in the 20th century for accommodation for mine workers.
Wattsville is the base for the Sirhowy valley country park, starting at the tourist centre in Full Moon Cottage (the site of a 19th-century village of Full moon), a site for hillwalking and mountain biking on the old railway trackbed.
It was located on the eastern edge of Wattsville and was the first colliery in South Wales to have electric lighting at the pithead and underground in 1892.
Just north-east of the village is Wattsville Castle, a four-storey drystone structure built by veteran Mikey Allen, construction of which began in 2019, and which became a local tourist attraction visited by over 10,000 people.
In 2024, after Caerphilly Council received a complaint, it was ordered to be demolished, a process expected to be completed in 2025.