Visitors will be able to see parts of Scotland’s Balmoral Castle used by the British royal family for the first time this summer. Guided tours of the royal family’s beloved private Scottish retreat will be available from July 1 to August 4, before the King and Queen arrive for their summer break in Aberdeenshire, with each group restricted to 10 people. Tickets for the “castle interior tour,” priced £100 ($126) or £150 ($188) with afternoon tea included, are limited to 40 tickets per day and are already selling fast. The Balmoral Castle website said the tours were the first since the castle wa…