I came across some of these building blocks once in a doctor’s surgery as a child. I was slightly baffled by them. They were so much like Lego, but… they weren’t Lego. How odd… At the time it made me feel like I might be losing it, and that it was lego, but I was perceiving incorrectly. But no, this was Tente!
Tente was less well known in the UK than in other European countries probably because it was a direct competitor to Lego. Lego of course was huge in the UK, and has been huge all around the world, but in some ways Tente was better. Tente were mostly multi-colored interlocking plastic bricks in different scales with wheels, minifigures, and various accessories, but the bricks were slightly larger than lego blocks.
They were first created in 1972 by a plastics and toy company in Barcelona, Spain and were sold worldwide with Hasbro selling the toys in the US and Japan (Hasbro are a huge company selling many classic toys like Transformers and My Little Pony. In the United States, Tente sets were typically found in specialty toy and model/hobby shops and not major toy retail stores.
They are no longer made, so have now of course fallen into the realm of collectibles as rare items, no doubt to be brought up to someone in the Antiques roadshow in 30 years time to be proclaimed priceless. I definitely preferred Lego at the time, but I'd rather a mint condition collection of Tente now...