Another thread reminded me of this. My story works better if you’ve seen the film “Hostel” 
(Adult) DD and I booked a weekend break in Poland. Booked an apartment on booking.com. Arrived, tried to get a taxi to the place but he dropped us off kerbside with a vague “it should be here somewhere”. We looked, all we could see was a building site. So we asked in an office block opposite. Receptionist looked on google and told us the address was said building site. We walked over to see 2 big burly men chatting in polish. Showed them my crumpled print out and no one said a word but one of the men jerked his head in the direction of a rickety lift. Feeling a little nervous at this point but got in and the lift itself wasn’t even finished, just bare boards.
He took us to an apartment and a sinister man said “come in”. At this point, slightly shitting ourselves. I look at my DD and she mouths to me “I’m scared” I mouth back “me too”. We pass a bathroom with the shower curtain drawn around the bath. He gives us a key and tells us our apartment is on the floor below. We go there and realise literally the only “finished” apartment is ours and the one upstairs. Put the TV on to try and break the aura of dread and it works for one minute then goes onto static! Then we hear what sounds like something being dragged across the floor in the apartment above us! We later worked out that it had actually started raining and the sound was distorted due to angled windows! But we didn’t realise that at the time. By this time it’s 10pm and realistically too late to run and go elsewhere!
We ended up barricading ourselves in the bedroom with a knife block we’d taken from the kitchen. We woke up in the morning and looked at each other and said “yes! We’re alive”. At this point I did think maybe we shouldn’t watch so many horror films! I later found out that it’s actually not that unusual for odd apartments in unfinished blocks to be rented out in this way. But at the time, all I could focus on was the digger outside and how easy it would be to hide our dead bodies in amongst the building works!
What’s been your scariest experience?