Question: What is the name of the peninsula that gymnast Kristina Guiourova was born in?

Context paragraphs:
Kristina Guiourova: Kristina Guiourova (Bulgarian: Кристина Гюрова ; born 17 February 1959 in Sofia, Bulgaria) is a former individual Bulgarian rhythmic gymnast.  She is the 1977 World All-around bronze medalist.

Daniel Gaudet: Daniel Gaudet also known as Dan Gaudet, was born on August 16, 1959, in Moncton, New Brunswick, Canada.  He was raised in Toronto and was educated at Agincourt Collegiate Institute and York University.  He is a former national gymnast and currently teaches Mathematics at the United World College of South East Asia in Singapore.  He is married (his wife was a teacher who used to work at the same school), and has two daughters, Kristina Gaudet and Cosette Gaudet.

Sofia: Sofia ( or or ; Bulgarian: София , "Sofiya ", ] ) is the capital and largest city of Bulgaria.  1.26 million people live in the city and 1.68 million people live in its metropolitan area.  The city is at the foot of Vitosha Mountain in the western part of the country.  Being in the centre of the Balkan peninsula, it is midway between the Black Sea and the Adriatic Sea, and closest to the Aegean Sea.

Kristina Wagner: Kristina Wagner (born Kristina Kay Crump on October 30, 1962) is an American actress best known for her role as Felicia Jones on the ABC soap opera "General Hospital".  She is sometimes credited by the name Kristina Malandro.  She also had a small role briefly on the ABC series "Hotel", in the late 1980s.

Toshiko Shirasu-Aihara: Toshiko Shirasu-Aihara (白須-相原 俊子, born June 3, 1939) is a retired Japanese gymnast.  She competed in all artistic gymnastics events at the 1960 and 1964 Olympics and won a team bronze medal in 1964.  Her best individual achievements were fourth places on the vault and uneven bars in 1964.  Born Toshiko Shirasu she changed her last name after marrying Nobuyuki Aihara, a fellow Olympic gymnast.  Their son Yutaka Aihara won a bronze medal in gymnastics at the 1992 Olympics.

Kristina Kliukevičiūtė: Kristina Kliukevičiūtė (born July 10, 1975 in Kaunas) is a Lithuanian rhythmic gymnast.

Tanya Chaplin: Tanya A. Chaplin (born Tanya A. Service; 1968) is an American gymnastics coach and former artistic gymnast.  She is the current head coach of the Oregon State Beavers women's gymnastics program and has been since 1997.  An accomplished competitive gymnast, Chaplin (who's maiden name was Service at the time) attended UCLA and was a member of the UCLA Bruins gymnastics team.

Taniko Nakamura-Mitsukuri: Taniko Nakamura-Mitsukuri (中村-三栗 多仁子, born March 23, 1943) is a retired Japanese gymnast.  She competed in all artistic gymnastics events at the 1964 and 1968 Olympics and won a team bronze medal in 1964.  Her best individual achievement was seventh place on uneven bars in 1968.  Born Taniko Nakamura she changed her last name after marrying Takashi Mitsukuri, a fellow Olympic gymnast.

Kristina Rangelova: Kristina Rangelova-Yankova (Bulgarian: Кристина Рангелова ; born January 24, 1985 in Sofia, Bulgaria) is a Bulgarian rhythmic gymnast.

Kristina Vaculik: Kristina Vaculik (born July 9, 1992) is a Canadian artistic gymnast who represented Canada at the 2012 Summer Olympics.  In 2011-2012, Vaculik took a year off from Stanford University, which she is attending on a gymnastics scholarship, in order to train full-time for the Olympics.

Supporting paragraphs: Kristina Guiourova Sofia
Answer: Balkan peninsula