Hotels in Salzburg have jacked up their prices, new figures show.Research by holiday information and price comparison platform Trivago (www.trivago.co.uk/hotelprices) shows today (Thurs) that a standard double room in the birthplace of composer Wolfgang Amadeus Mozart currently costs 122 Euros, up sharply by 20 Euros to the previous month.Tens of thousands of holidaymakers are coming to the city these days to enjoy its architecture and various sights in the comfortable weather conditions. The Osterfestspiele (Easter Festival), a series of concerts and opera, is a popular attraction set to help Salzburgs hotels to a rise in bookings in the coming days despite increasing prices.Trivagos investigations also show that hotels in Graz became more expensive as well from March to the current month. Resorts in the second-biggest city of Austria currently charge 111 Euros for a double room, up from 102 Euros last month.Hotels in Linz (97 Euros; March: 136 Euros) and Innsbruck (110 Euros; March: 113 Euros) however slashed their prices. The price for a double room at hotels in Vienna (128 Euros; March: 134 Euros) dropped too, according to Trivago.Geneva (222 Euros) in Switzerland and the Italian city of Venice (208 Euros) have been identified as the most expensive holiday destinations of Europe by Trivago when it comes to hotel room prices.Meanwhile, hotels and guesthouses in Vienna have experienced the most successful March of all times. Resorts in the Austrian capital registered 867,000 overnight stays last month, up by 3.3 per cent compared to the same month of 2010. Officials stressed that the number of overnight stays by Russians soared by 52 per cent. They also pointed out that several international congresses took place in Vienna last month.Figures for this month could outpace the statistics for April 2010 as 32,000 professional and amateur athletes participated in the various competitions of the Vienna City Marathon (VCM) last Sunday.Vienna had 10.2 million overnight stays last year more than ever before. The city recorded 1.996 million overnight stays in the first three months of this year, up by 1.8 per cent compared to the same time span in the record year 2010.