Attendance at the Wisconsin Historical Society's 12 historic sites is up 15.7 percent this summer, according to a press release.

"Through the end of July 2013, paid attendance is up 29.9 percent at Old World Wisconsin, 38.7 percent at Wade House and 13.5 percent at Circus World Museum. System-wide attendance revenue is also up by almost 22 percent compared to the same time last year," said the Historical Society.

The society cited factors like last year's intense heat, this summer's family-friendly World of Little House and Life of the Farm programming at Old World Wisconsin as well as additions to sites like Old Wade House and Lake Geneva's Black Point Estate.

Click here for a listing of historic sites in Wisconsin, including those belonging to the Wisconsin Historical Society.