At the heart of Colchester are the remains of its castle, a ruggedly imposing, honey-coloured keep, set in attractive parkland stretching down to the River Colne. Begun less than ten years after the Battle of Hastings, the keep was the largest in Europe at the time, built on the site of the Temple of Claudius. Inside the keep, a museum holds an excellent collection of Romano-British archeological finds, notably a miscellany of coins and tombstones. The museum also runs regular guided tours, giving access to the Roman vaults, the Norman chapel and the castle roof, which are otherwise out of bounds. Outside, down towards the river in Castle Park, is a section of the old Roman walls, whose battered remains are still visible around much of the town centre. They were erected after Boudicca had sacked the city and, as such, are a case of too little too late.