Salines d'Es Trenc

An alga living in extremely salty water produces a red pigment. The higher the salt concentration in a pool, the stronger its colour. The pink is an indicator of salinity.

The same alga feeds tiny crustaceans, which are eaten by flamingos. Their pink feathers get their colour from the same source.

The Salobrar de Campos is one of the Balearics’ most important wetlands, with more than two hundred bird species recorded. Shallow salt pools are rich feeding grounds for waders, with plenty of food in the mud.

The busiest periods are spring and autumn, when birds stop here on migration between Europe and Africa. Flamingos, avocets, black-winged stilts and plovers can gather in their hundreds.

A tip from experience: bring binoculars. The birds stay well away from the paths. Without magnification, a flamingo may be little more than a pink dot in the distance. Binoculars make a real difference to a walk here.

The process is old and straightforward. Seawater is channelled into shallow pools and left to evaporate in the sun over several weeks. The brine becomes more concentrated as it passes from pool to pool — which also explains the changing colour — until salt crystallises.

The harvest takes place in July and August. Machines push salt from the bottom of the pools into white heaps, which stand beside them for days while they drain. This is when the saltworks look most impressive.

One variety is still harvested by hand: flor de sal, the fine crust that forms on the water’s surface in calm weather. Workers skim it with flat scoops before it sinks, which helps explain the price.

For a closer look at the process, join a guided tour. It takes around 45 minutes, following the water’s journey from the first pool to the finished bag of salt.

September is the best month. The salt heaps remain, the colours are strong and visitor numbers ease. October comes a close second for the warm light across the pools.

In March and April, migrating birds stop here — the best time of year if you bring binoculars.

In winter, the pools are full of water and their colours are pale. In high summer, there is no shade or drinking water out among the pools. Late afternoon is better than midday, and the colours are deeper then too.