Iranian tower tomb that's a UNESCO World Heritage Site
22A
Pitcher's stat.
23A
Charged particle
24A
Like some 43-Across that are easier on the stomach
28A
Tallest building in Pittsburgh
32A
"____ be fun, they said..."
34A
Sault ___ Marie, MI
35A
More so suffix
36A
Well-known Islamic shrine in Jerusalem
41A
"Oh, I can just ____ it over!" (phrase that hasn't been said in forever)
42A
Extinct New Zealand bird
43A
They can be blond and pale
44A
What would have been the tallest building in not only the Windy City, but the entire Western Hemisphere, if it had been completed
49A
Late night host whose hair looks remarkably like a cockatoo
50A
English translation of a colorful card game
51A
Place for a cat nap
54A
Atypical wind-powered structure in Kent, England
59A
Tahoe or Crater, for example
62A
Woodwind instrument
63A
"Nobody Knows the Trouble I've ___" (African-American spiritual song)
64A
Doubleday rumored to have created baseball
65A
Prefix that could very fittingly go in front of 20-Across
66A
Size up from a queen
67A
Tests for H.S. juniors
68A
Antlered animals
Down
1D
Character in "My Cousin Vinny" that asks "Are you mocking me with that outfit?"
2D
E in baseball scorebooks
3D
2014 Bleachers hit "I ____ Get Better"
4D
Messy person
5D
Statements of belief
6D
"I _____ got a clue!"
7D
Baghdad's country
8D
Type of palm tree, or how the Knights from a Monthy Python movie might say "No, father!"
9D
Pretentious one
10D
Alexandria _____-Cortez
11D
Singer Benatar
12D
New Year's ___
13D
Character decapitated at the end of season 1 of "Game of Thrones" (spoiler, sorry, but if you haven't seen it by now you probably weren't going to anyway)
19D
Smallest in the litter
21D
"Clean up on ____ 4"
25D
Not just once
26D
Stinks to high heaven
27D
Bobby of hocky fame
28D
City where Einstein was born
29D
¿Cómo ____?
30D
Biblical verb ending
31D
Wrangler competitor
32D
What Boise State should actually be called, since Boise isn't a state
33D
Poison
37D
Texter's "No way!"
38D
____ Fighters
39D
Steakhouse orders that might still be mooing
40D
____ Miss
41D
Gov't agency whose leader was once spotted drinking out of a massive mug