Probably the cheapest option is to fly directly via Czech Airlines www.CSA.cz with some offers ranging from 150eur return, or use a low-cost carrier like Ryan Air www.RyanAir.com. Ryan Air or Air Lingus www.AirLingus.com can fly you to Prague from 24 EUR, tax excluded, one way. Another option is to fly to London or Glasgow and then use another low-cost airline like Easy Jet.
Free Prague Walking Tour
During the 4-hour walking tour of Prague, you will be introduced to the most interesting and significant historical sites in Prague, such as the Jewish Quarter, the historical buildings of the Old Town and the renowned Charles Bridge, before finishing off at the Prague Castle.