Topography (is the study of the shape and features of land surfaces. The topography of an area could refer to the surface shapes and features themselves, or a description (especially their depiction in maps))

Uzbekistan is a Central Asian nation and former Soviet republic. It's known for its mosques, mausoleums and other sites linked to the Silk Road, the ancient trade route between China and the Mediterranean. Samarkand, a major city on the route, contains a landmark of Islamic architecture: the Registan, a plaza bordered by 3 ornate, mosaic-covered religious schools dating to the 15th and 17th centuries.

Vigenère Cipher (is a method of encrypting alphabetic text by using a series of interwoven Caesar ciphers, based on the letters of a keyword. It employs a form of polyalphabetic substitution. First described by Giovan Battista Bellaso in 1553, the cipher is easy to understand and implement, but it resisted all attempts to break it until 1863, three centuries later. This earned it the description le chiffre indéchiffrable (Frenchfor 'the indecipherable cipher'))

Calling it a night.............................

Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. They are an informal grouping within the infraorder Cetacea, usually excluding dolphins and porpoises. Whales, dolphins and porpoises belong to the order Cetartiodactyla, which consists of even-toed ungulates

X-ray Crystallography (is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their crystallographic disorder, and various other information)

Off to work.............................

Yosemite National Park - is an American national park located in the western Sierra Nevada of Central California, bounded on the southeast by Sierra National Forest and on the northwest by Stanislaus National Forest. The park is managed by the National Park Service and covers an area of 748,436 acres and sits in four counties. Designated a World Heritage Site in 1984, Yosemite is internationally recognized for its granite cliffs, waterfalls, clear streams, giant sequoia groves, lakes, mountains, meadows, glaciers, and biological diversity. Almost 95% of the park is designated wilderness. On average, about four million people visit Yosemite each year, and most spend the majority of their time in the seven square miles of Yosemite Valley. The park set a visitation record in 2016, surpassing five million visitors for the first time in its history.

Yosemite Valley

It's been more than 24 hours since I posted "Y" so I'll continue with "Z".

Keeping with the same theme ...

Zion National Park - is an American national park located in southwestern Utah near the town of Springdale. A prominent feature of the 229-square-mile park is Zion Canyon, which is 15 miles long and up to 2,640 ft deep. The canyon walls are reddish and tan-colored Navajo Sandstone eroded by the North Fork of the Virgin River. The lowest point in the park is 3,666 ft at Coalpits Wash and the highest peak is 8,726 ft at Horse Ranch Mountain. Located at the junction of the Colorado Plateau, Great Basin, and Mojave Desert regions, the park has a unique geography and a variety of life zones that allow for unusual plant and animal diversity. Numerous plant species as well as 289 species of birds, 75 mammals (including 19 species of bat), and 32 reptiles inhabit the park's four life zones: desert, riparian, woodland, and coniferous forest. Zion National Park includes mountains, canyons, buttes, mesas, monoliths, rivers, slot canyons, and natural arches.

Zion Canyon

The Apennines or Apennine Mountains are a mountain range consisting of parallel smaller chains extending c. 1,200 km along the length of peninsular Italy. In the northwest they join with the Ligurian Alps at Altare. In the southwest they end at Reggio di Calabria, the coastal city at the tip of the peninsula.

Round 9 ...

The Baltic Sea - is an arm of the Atlantic Ocean, enclosed by Denmark, Estonia, Finland, Latvia, Lithuania, Sweden, northeast Germany, Poland, Russia and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and from 10°E to 30°E longitude. A marginal sea of the Atlantic, there is limited water exchange between the two water bodies. The Baltic Sea is connected by artificial waterways to the White Sea via the White Sea-Baltic Canal and to the German Bight of the North Sea via the Kiel Canal. In recent years, it has become popular with the cruise industry.

The Canary Islands, a Spanish archipelago off the coast of northwestern Africa, are rugged volcanic isles known for their black- and white-sand beaches. Tenerife, the largest island, is dominated by the sometimes-snowy active volcano Mt. Teide, which has its own astronomical observatory and is part of Teide National Park. Tenerife hosts a huge pre-Lent Carnival in the capital, Santa Cruz de Tenerife.