What Are These I Saw On Holiday?

[Tim330]

Taken last week near a beach in the resort of Playa Blanca, Lanzarote. I thought some sort of volcanic measuring devices but don't have a clue. A few boxes had open doors.

[Tim330]

https://maps.google.co.uk/maps?hl=en-GB&q=play...

Here it is. Not sure how to look at the archived photos though. Old holiday homes does make sense though

[Tim330]

Sorry my google map link was to the wrong place. It was further round to the right (north east. But mystery solved, thanks