Saudi Arabia opened to general tourism only in 2019, and the sites are still being developed for visitors: the Nabataean tombs at AlUla, comparable in style to Petra, the historic Diriyah district near Riyadh, and Jeddah's old town on the Red Sea coast.
The guides here cover Saudi Arabia as a whole. Tourist e-visas are available to many nationalities. Mecca and Medina are restricted to Muslims, and this applies to the cities themselves, not only the mosques. Summer heat is extreme across the country, leaving roughly November to March as the comfortable window. Dress and behaviour rules are stricter than in neighbouring Gulf states.