We first went to Cornwall in summer 2016 and loved it so much we went back for longer in summer 2017. There are a lot of areas with Poldark-related themes; let me see if I can recall what we saw (I'm sure you can search online for more). If I have time I will haul out my Poldark fan's map of Cornwall. The Geevor tin mine had some Poldark displays (and is worth a visit anyway!); Rick Steves had visited the week before we were there. I see they mention Poldark on their home page. Poldark is big business in Cornwall, but even bigger business seems to be the German tourists who come because of a German series based on the novels of Rosamunde Pilcher.
We had Sunday roast at a public house (the North Inn) in Pendeen (near Geevor tin mine) whose proprietor has been an extra (I'm not sure if they mean the earlier series or the current one!). Ah, here is a quote from their website (linked in the pub name): "This is very much Poldark country and John, the landlord, will be appearing as an extra in the forthcoming series."
We love to hike, and saw places on the Lizard peninsula where scenes from Poldark had been filmed. (If you join one of the Cornwall groups on social media, people post pictures of Poldark actors and crew during filming!) The landscape is stunning, with rocky cliffs, hidden coves and beaches, old churches, and history with smugglers, prehistoric standing stones, the footsteps of Arthur Conan Doyle and Marconi (there's a small museum), etc., etc. Check out Tony Robinson's walk through Cornwall. We've stayed in Marazion (fantastic location – close to all this, and Minack Theatre, St Michael's Mount, etc.), Praa Sands, and Dartmoor (from which Doc Martin's Port Isaac was an easy drive). Cadgwith Cove was just one of many lovely places we hiked to. I miss Cornish ice cream and their cream teas ....
Enjoy! We love Cornwall, and feel we've only scratched the surface. I want to go back and see the church St Just in Roseland, the Lost Gardens of Heligan, and mostly just hike around the Lizard Peninsula and maybe do the (whole?) Southwest Coastal Path someday ...