Bulgaria, General, Effect of acid rain on forest.

Spain, Catalonia, Barcelona, Interior of the Sagrada Familia designed by Antoni Gaudi, Mathew, Mark, Luke, John columns, Temple ceiling with kaleidoscopic effect.

Spain, Catalonia, Barcelona, Interior of the Sagrada Familia designed by Antoni Gaudi, Mathew, Mark, Luke, John columns, Temple ceiling with kaleidoscopic effect.

Spain, Catalonia, Barcelona, Interior of the Sagrada Familia designed by Antoni Gaudi, Mathew, Mark, Luke, John columns, Temple ceiling with kaleidoscopic effect.

Animals, Birds, A male Black-bellied Hummingbird, Euperusa nigriventris, and Hairy Heliconia flower, Heliconia vellerigera, in Costa Rica. Photographed in high key for artistic effect.

Animals, Birds, A male Coppery-headed Emerald Hummingbird, Elvira cupreiceps, feeds on the nector of a neotropical blueberry flower in Costa Rica. Photographed in high key for artistic effect.

Animals, Birds, A Green Thorntail Hummingbird, Discosura conversii, feeding on the nector of a tropical blueberry flower in Costa Rica. Photographed in high key lighting for artistic effect.

Animals, Birds, A female Green-crowned Brilliant Hummingbird, Heliodoxa jacula, approaches a tropical blueberry flower to feed in Costa Rica. Photographed in high key for artistic effect.

Animals, Birds, A female Green-crowned Brilliant Hummingbird, Heliodoxa jacula, approaches a Hairy Heliconia flower to feed in Costa Rica. Photographed in high key for artistic effect.

Animals, Birds, A female Purple-throated Mountain-gem Hummingbird, Lamporis calolaemus, photographed in high key lighting for artistic effect. Costa Rica

Animals, Birds, A male White-bellied Mountain-gem Hummingbird, Lampornis hemileucus, feeds on a tropical blueberry flower in Costa Rica. Photographed in high key lighting for artistic effect.

Animals, Bird, Hummingbird, A male Violet Sabrewing Hummingbird, Campylopterus hemileucurus, hovers at a tropical Hairy Heliconia, Heliconia vellerigera, to feed on nectar in Costa Rica.