Rafters exercise in Pinios river, in Tempi Valley, Thessaly, Greece, June 27, 2018. Tempi Valley, a gorge in northern Thessaly, is one of the favorite places for rafters as it offers thrilling experiences amidst impressive natural landscapes. (Xinhua/Apostolos Domalis)

Rafters exercise in Pinios river, in Tempi Valley, Thessaly, Greece, June 27, 2018. Tempi Valley, a gorge in northern Thessaly, is one of the favorite places for rafters as it offers thrilling experiences amidst impressive natural landscapes. (Xinhua/Apostolos Domalis)

Rafters prepare for canyon rafting in Pinios river, in Tempi Valley, Thessaly, Greece, June 27, 2018. Tempi Valley, a gorge in northern Thessaly, is one of the favorite places for rafters as it offers thrilling experiences amidst impressive natural landscapes. (Xinhua/Apostolos Domalis)

Rafters prepare for canyon rafting in Pinios river, in Tempi Valley, Thessaly, Greece, June 27, 2018. Tempi Valley, a gorge in northern Thessaly, is one of the favorite places for rafters as it offers thrilling experiences amidst impressive natural landscapes. (Xinhua/Apostolos Domalis)

Rafters prepare for canyon rafting in Pinios river, in Tempi Valley, Thessaly, Greece, June 27, 2018. Tempi Valley, a gorge in northern Thessaly, is one of the favorite places for rafters as it offers thrilling experiences amidst impressive natural landscapes. (Xinhua/Apostolos Domalis)

Rafters exercise in Pinios river, in Tempi Valley, Thessaly, Greece, June 27, 2018. Tempi Valley, a gorge in northern Thessaly, is one of the favorite places for rafters as it offers thrilling experiences amidst impressive natural landscapes. (Xinhua/Apostolos Domalis)