One of, if not the most important centres for justice and peace in the world, Peace Palace comprises the United Nations International Court of Justice, the Permanent Court of Arbitration, the Hague Academy of International Law and the Peace Palace Library. Although this is a working palace, which means most areas are closed to the public, there is, however, a visitors centre where those interested can learn more about the history of the palace and the role it plays today in international justice via a free audio tour. On rare occasions, the palace opens its doors to the public for guided tours, but it is advisable to check well in advance if any dates are available as they are few and far between. In any case, the impressive surrounding gardens and Neo-Renaissance buildings are definitely a must-see.

Ross Castle is a classic 15th century, with square bartizans on diagonally opposite corners and a thick end wall containing a tier of chambers and winding stairs.

Muckross Abbey is a major ecclesiastical site situated in Killarney National Park. It was founded in 1448 as a Franciscan friary by Donal McCarthy Mor and is in a remarkable state of preservation.

The Royal Opera House is a relatively recent (it opened in 2011), yet critical addition to the Omani cultural scene where the Sultan Qaboos bin Said Al Said himself is a regular. Sleek on the outside, the white-stone building boasts elaborate inner décor that serves as the backdrop to some of the world’s finest performances.