Question: Giovanni Battista Castiglione was imprisoned in a tower located on the north bank of which river ?

Context paragraphs:
Belzoni, Mississippi: Belzoni ( ) is a city in Humphreys County, Mississippi, in the Mississippi Delta region, on the Yazoo River.  The population was 2,235 at the 2010 census.  It is the county seat of Humphreys County.  It was named for the 19th-century Italian archaeologist/explorer Giovanni Battista Belzoni.

Santi Giovanni Battista e Floriano, Fossombrone: Santi Giovanni Battista e Floriano is a Renaissance architecture Roman Catholic church and adjacent Franciscan convent are located on Piazza San Giovanni in the frazione of Isola di Fano in Fossombrone, region of Marche, Italy.

Giovanni Battista Castiglione: Giovanni Battista Castiglione (1516–1598) was the Italian tutor of Princess (later Queen) Elizabeth I.  It is speculated that he taught Prince (later King) Edward VI.  A humanist reformer, he was imprisoned in the Tower of London in 1556 by Elizabeth's sister, Mary I.  Suspected of sedition, he was tortured so severely that he was left permanently lame.  Later, he carried Elizabeth's letters when she herself was imprisoned in the Tower.

San Giovanni Battista, Livorno: San Giovanni Battista is a Baroque-Mannerist style, Roman Catholic church located at the crossing of "Via San Giovanni" and "Via Carraia" in central Livorno, region of Tuscany, Italy.

Church of San Giovanni Battista, Mogno: The Church of San Giovanni Battista (Italian: "Chiesa di San Giovanni Battista" ; German: "Kirche San Giovanni Battista" ) is located in the alpine village of Mogno in the Swiss canton of Ticino.  It was built between 1994 and 1996 on the site of an older church (from 1626), which was levelled by an avalanche in 1986.  The church is named after St John the Baptist.

Agustín Codazzi, Cesar: Agustín Codazzi, or Codazzi, is a city and municipality of the Department of Cesar in Colombia.  It was founded in 1784 by the Spanish Captain Salvador Felix de Arias with the name of "El Pueblito del Espiritu Santo" but later renamed after the Italian cartographer, Giovanni Battista Agostino Codazzi, who died in this place in 1859.  It is located along the Serranía del Perijá, covering some of the area pertaining to the valley of the Cesar River.

Farmacia del Moro, Florence: The Farmacia del Moro, also called Farmacia del Saraceno (referencing Moor and Saracen) was a pharmacy located facing Piazza San Giovanni and the San Giovanni Battista Baptistry in Florence, region of Tuscany, Italy.  The locale originally faced Via Cerretani, facing Canto alla Paglia.

Accademia Ligustica di Belle Arti: The Accademia Ligustica di Belle Arti is a tertiary academy of fine arts located in Genoa, Italy.  It also houses a museum (Museo dell'Accademia Ligustica di Belle Arti), which includes works of Giovanni Benedetto Castiglione, Giuseppe Abbati, Anton Raphael Mengs, Perin del Vaga, Luca Cambiaso, Bernardo Strozzi, Giovanni Battista Paggi, Sinibaldo Scorza, Domenico Fiasella, Luciano Borzone, Serafino De Tivoli, Plinio Nomellini.  The academy was founded in 1751.

Tower of London: The Tower of London, officially Her Majesty's Royal Palace and Fortress of the Tower of London, is a historic castle located on the north bank of the River Thames in central London.  It lies within the London Borough of Tower Hamlets, separated from the eastern edge of the square mile of the City of London by the open space known as Tower Hill.  It was founded towards the end of 1066 as part of the Norman Conquest of England.  The White Tower, which gives the entire castle its name, was built by William the Conqueror in 1078 and was a resented symbol of oppression, inflicted upon London by the new ruling elite.  The castle was used as a prison from 1100 (Ranulf Flambard) until 1952 (Kray twins), although that was not its primary purpose.  A grand palace early in its history, it served as a royal residence.  As a whole, the Tower is a complex of several buildings set within two concentric rings of defensive walls and a moat.  There were several phases of expansion, mainly under Kings Richard the Lionheart, Henry III, and Edward I in the 12th and 13th centuries.  The general layout established by the late 13th century remains despite later activity on the site.

San Giovanni Battista, Praiano: The Church of San Giovanni Battista (Italian: "Chiesa di San Giovanni Battista" ) is a church located in the center of Praiano, a small "comune" located on the Amalfi Coast in southern Italy.  Constructed in the Romanesque style, San Giovanni Battista has a rectangular plan and a vaulted ceiling, featuring Italian Baroque design elements on the inside.  Dating back to the 11th–12th centuries, the church features a very well preserved maiolica flora- and fauna-inspired tiled floor and a pipe organ from Neapolitan organ masters.

Supporting paragraphs: Giovanni Battista Castiglione Tower of London
Answer: River Thames