This is the view from the north. The only significant part of the castle that remains is the 14th century gatehouse, seen here. It sits atop a hill with extensive views, an ideal defensive site. After the first Battle of Newbury in 1643 it was occupied by Colonel John Boys, a supporter of Charles 1st. He improved the defences and in 1644 he resisted two major attacks by the Parliamentary troops. He only surrendered the castle in the Spring of 1646 when ordered to do so by the King, and the garrison was allowed to leave peacefully and join the rest of the King's army near Wallingford. I'm sure they complied with the sign on the gate.