|Elevation||1,201 ft (366 m)|
|Time zone||Central (CST) (UTC-6)|
|• Summer (DST)||CDT (UTC-5)|
|GNIS feature ID||1379514|
Castell is a small unincorporated riverside town in Llano County, Texas, United States. The population was 104 at the 2010 census. Located in the heart of the Texas Hill Country, its northern border is formed by the Llano River. Designated a Recorded Texas Historic Landmark in 1964, Marker number 9440. 
It was part of a series of five immigrant settlements sponsored by a group of prominent Germans known as the Adelsverein, including Count Emil von Kriewitz, John O. Meusebach, Prince Carl of Solms-Braunfels, Hermann Spiess, Gustav Schleicher, Ferdinand Ludwig Herff and Count Carl Frederick Christion of Castell-Castell (1801–1850). Count Castell was the Vice President and Business Manager from the beginning of the Adelsverein until about the time of Castel's founding. The other communities were Schoenburg, Meerholz, Leiningen, and Bettina. The first two were unsuccessful from the start. Leiningen and Bettina had brief lives, Bettina lasting only a year. Only Castell remains.
Describing conditions in Castell in the mid-19th century, a tour guide has written
|“||Life here was not easy. For the first couple of years, Castellites depended heavily on supplies and support from the people of Fredericksburg, who had problems enough of their own. A round trip to Fredericksburg—about 50 miles—took 4 days.||”|
Castell briefly experienced an influx of about 20 Mormon pioneer families under the leadership of Lyman Wight. They had settled in Zodiac, Texas, in 1847, in Mormon Mill in 1851, and then settled in Castell briefly before moving south in 1854 to Bandera, Texas. Wight died on March 31, 1858, and his body was returned to Zodiac for burial. Due to the Mormon custom of sending out missionaries, the Castellite congregations of 19th-century North Carolina possibly took their name from the Mormons who lived briefly in Castell, Texas.
The community was originally on the north bank of the Llano River but now is on the south bank in the western part of Llano County near the Mason County line.
Castell has several small businesses, mainly centering around camping and hospitality as a result of the flyfishing and kayaking opportunities there.
- Emil Kriewitz lived with the Penateka Comanche, and served as guide for Fisher-Miller Land Grant settlers. He was the Llano County justice of the peace in 1970, Llano County election judge in 1871, and postmaster of Castell from 1876 to 1883. He was buried in the Llano City Cemetery.
- "American FactFinder". United States Census Bureau. Retrieved 2008-01-31.
- "US Board on Geographic Names". United States Geological Survey. 2007-10-25. Retrieved 2008-01-31.
- "Castell, Texas". Recorded Texas Historic Landmark. William Nienke, Sam Morrow. Retrieved 14 February 2011.
- Lyman Wight's Mormon Colony in Texas excerpt from "Mormon Trails" chapter in Hill Country travel guide by Richard Zelade (2001). Accessed August 6, 2007.
- Castell, Texas by James B. Heckert-Greene in the Handbook of Texas Online. Accessed August 7, 2007.
- Lyman Wight at Find a Grave
- Castell, Texas — 76831, basic information about the town. Accessed August 7, 2007.
- Castell, Texas
- Emil Kriewitz at Find a Grave
- Hadeler, Glenn. "Emil von Kriewitz de Czepry". Handbook of Texas Online. Texas State Historical Association. Retrieved 17 February 2011.
- Castell, Texas Community Profile includes numerous links to various Castell maps, aerial photos, Census data, local government offices. Accessed August 7, 2007.
- Castell, Texas — 76831, a reference to the area's zip code, with information about the town's business community and photo of plaque commemorating the founding of Castell, Bettina, and Leiningen. Accessed August 7, 2007.
- Biography (English) of Count Carl of Castell-Castell