Trolley bus

there is usually a timetable at the stops when you find them

It’s actually a train 

A trolleybus (also known as trolley bus, trolley coach, trackless trolley, trackless tram – in the 1910s and 1920s[1] – or trolley[2][3]) is an electric bus that draws power from dual overhead wires (generally suspended from roadside posts) using spring-loaded trolley poles. Two wires, and two trolley poles, are required to complete the electrical circuit. This differs from a tram or streetcar, which normally uses the track as the return path, needing only one wire and one pole (or pantograph

The one stop I know of is outside the Aparthotel Reina, I’ve seen it there many many times … but I don’t recall seeing a timetable there.

Well if you want to be really pedantic it's actually called the Tren Turistico and not really a train as the definition of a train is something that runs on railways

A train (from Old French trahiner, from Latin trahere, "to pull, to draw"[1]) is a series of connected vehicles that run along a railway track and transport people or freight. Trains are typically pulled or pushed by locomotives (often known simply as "engines"), though some are self-propelled, such as multiple units or railcars. Passengers and cargo are carried in railroad cars, also known as wagons or carriages. Trains are designed to a certain gauge, or distance between rails. Trains operate on steel tracks with steel wheels, the low friction of which makes them more efficient than other forms of transport.

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