The flow of water from Volvi to Strymonikos Gulf, through the river Richios, creates an idyllic environment between Rentina and Stavros. The valley that is fed by the overflow of the lake, in the wide gorge created by Holomontas and Kerdyllia, belongs to the protected areas Natura 2000 and is known as "Macedonian Tempi" or simply "Straits of Rentina". The location was an important passage in antiquity and Byzantine times, which was also called "thieves' strait". The large Byzantine Castle of Rentina, which overlooks the entire valley, confirms that it was necessary to supervise the passage from ancient times, while the straits are mentioned by Euripides and it is probable that his tomb is located in the area.
The verdant, riparian forest that grows on both sides of the Richio riverbed is characterized by the abundance of large trees and especially plane trees, willows, lindens, and elms, with climbing plants that cover the trunks and foliage creating an impressive sight. The morphology changes in every season but also every year, as it depends on the height of the overflow in Lake Volvi and the volume of water that will be channeled, resulting in the forest of Macedonian Tempi being different every time someone visits it. It maintains a great variety and density in shrubs, with intense vegetation throughout the area of about 650,000 sq.m. from the eastern banks of the Volvi to the shores of Stavros, where Richios ends.
The Macedonian Tempi are home to many bird species (87 species have been identified and are included in the Important Bird Areas of Greece) and especially predators, as the fauna offers a variety of reptiles and small mammals. The beauty of the landscape but also the relatively comfortable route of eight, approximately, kilometers that cross the straits, make it an amazing hiking and cycling path, at a distance of about 65 kilometers from Thessaloniki.