Cardiff is a vibrant capital where old stone meets modern glass along the waterfront. The city centre has a massive castle where Roman ruins sit under a grand Victorian palace. My top tip is to explore the glass-roofed stalls of the central market for fresh Welsh cakes. You can walk through the green trees of Bute Park or visit the huge whale skeleton at the National Museum for free. To the south, the bay offers a wide lagoon and the copper arts centre. The scent of salt air and coffee drifts through the Victorian arcades. Life here follows the rhythm of major sports and the local arts scene. It is a fine spot for a city break with dogs welcome in the parks.