Pacific evergreen with orange-red bark / FRI 10-1-21 / Fictional home with a secret basement / Written designs that are also readable when flipped or rotated

Constructor: Jim Horne and Jeff Chen

Relative difficulty: Easy-Medium

THEME: THE BAT CAVE (57A: Locale below 17-Across, as suggested by three images in this puzzle's grid)  — there are three black-square configurations in the grid that are supposed to represent bats, which makes ... the whole grid, I guess ... a representation of THE BAT CAVE, which sits, as the clue states, below WAYNE MANOR (17A: Fictional home with a secret basement)

Word of the Day: Caber TOSS (13D: Caber ___ (Scottish athletic event)) —

The caber toss is a traditional Scottish athletic event in which competitors toss a large tapered pole called a "caber" (/ˈkeɪbə/). It is normally practised at the Scottish Highland Games. In Scotland the caber is usually made from a Larch tree and it can be between 16–20 feet (4.9–6.1 m) tall and weighs between 90–150 pounds (6.4–10.7 st; 41–68 kg). The term "caber" derives from the Gaelic word cabar, which refers to a wooden beam. (wikipedia)

• • •

MADRONA

Really really feel like I've seen this conceit before. Not THE BAT CAVE, exactly, but the whole "look, these black squares are actually bats" thing. They could just as easily be moths or threes or "E"s but if you say "bat," then OK, that's what they are. Not really getting where the "cave" is, or how it is "suggested" by anything in this puzzle. I guess this is supposed to be a Halloween-ish theme, because it's the first of October ... the month that contains Halloween? I'm having to infer a lot today. I'll spare you all my usual complaining about themed Fridays (or Saturdays), since I've been over all that so many times. Today's grid did have a typical themeless answer count (72), but did not feel like it, probably because of the seeming preponderance of very short answers. Lots more 3s and 4a than I expect (or typically want) to see in my late-week themelesses. But the grid seems solid enough, and if you like whimsy in your grid design, this definitely has it. Not much to get excited about in the fill, though SHOVEL-READY is pretty nice, and I kind of like the clue on RADAR SCREEN (35A: Range of consideration, metaphorically). I'd never heard of MADRONA or AMBIGRAMS, so there was some hold-up there (the MADRONA hold-up being more serious because it prevented me from turning a corner, from the NW into the W), but mostly this felt easy. 

Five things:

• 62A: ___ urbis conditae (ANNO) — "in the year since the founding of the city"; the city in question is Rome, and "AUC" (or "AVC") was used as a dating system, with the traditional date of Rome's founding (753 B.C.E.) used as the reference point. As wikipedia usefully points out, the year 1 B.C.E. would be 753 AUC, and 2021 would be 2774 AUC. It's a weird phrase to expect people to know. 
• 4A: Like Marcia, among the Brady Bunch" daughters (ELDEST) — I (still) never know if an answer like this is going to be OLDEST or ELDEST. Looks like ELDEST is more typically used for people.
• 29D: Driver around a lot? (ADAM) — ADAM Driver is an actor, so presumably he can (sometimes) be found around a (movie) lot.
• 
  42D: Jaime ___ a.k.a. the Bionic Woman (SOMMERS) — I grew up with the Bionic Woman as an iconic TV figure. My sister once got a Jaime SOMMERS head where you could style ... her hair, I guess, though now that I think about it, what the hell is "bionic" about her hair. They were probably just trying to turn Jaime into a conventional "girls" toy, and I guess it worked, though the toy didn't survive the Christmas season—my sister left Jaime's head in front of the fire one evening and Jaime's face just melted and caved in. Very memorable and awesome childhood experience. My main point here was going to be that I thought she was a "Jamie," not a "Jaime," but the melted-face story was fun to relive. Jaime SOMMERS was played by Lindsay Wagner, who was also in the first "Rockford Files" episode, as well as the movie "The Paper Chase," which I just watched. She's Houseman's daughter. I know a weird lot of Jaime SOMMERS-related stuff.
• 52D: Inits. that often precede "+" (LGBTQ) — I really like this clue. The queerness angle comes as a complete surprise. You do not see it coming. Clue looks mathy or maybe sciencey, and then boom, rainbow flag. Enjoyed that discovery.

Signed, Rex Parker, King of CrossWorld

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