Edinburgh Castle had its busiest day ever with more than 11,300 paying visitors recorded on 16 July.
The castle is already Scotland's top paid-for tourist attraction, with 755,001 visitors between April and July - an increase of 8% on last year.
Historic Scotland said it also recorded 1.96 million visits to their 77 attractions across Scotland during the same period, 9% more than last year.
Several other paid-for heritage sites also broke their records.
Stirling Castle was second most popular attraction between April and July, with 215,461 visitors, while Urquhart Castle on the banks of Loch Ness was third with a 9% visitor increase to 192,191.
The Neolithic settlement of Skara Brae in Orkney took fourth spot, recording 56,386 visitors.
Doune Castle's jump to fifth place was credited to its TV role as the fictional Castle Leoch in the Outlander series which helped attract 40,751 visitors, a 23% increase.
Other attractions in the top ten are Linlithgow Palace, Iona Abbey, St Andrews Castle, Fort George in Inverness and Melrose Abbey.
Stephen Duncan, commercial and tourism director at Historic Environment Scotland, said: "This season has brought with it a raft of impressive new records and achievements for a number of our Historic Scotland attractions.
"With just under two million people turning out at our castles, palaces, abbeys and other historic sites throughout the country over a four-month period - it's proving to be a season for the record books."