Task: Question Answering
Input (English): Passage: The college presents a symmetrical front to New Road and the castle mound, with four small gables between a larger gable at either end. There are two quadrangles, with steps leading down from the upper quadrangle (to the east) to the lower quadrangle (to the west). Residential accommodation for students and fellows is located in the lower quadrangle, whilst the hall, library, and administrative offices are in the upper quadrangle. The buildings are two storeys high, with dormers above. There are pools in the centre of the quadrangles (the one in the lower quadrangle is the longer of the two); the writer Simon Jenkins said that these are "almost puddles", and saw them as relics of Harrison's Mediterranean plan. The writer Peter Sager, however, thought that the pond represents the canal basin that previously occupied the site. The main entrance leads into the upper quadrangle, which has the hall on its east side. The square-mullioned windows facing the quadrangles are arranged in close-set groups of three; at the east end of the upper quadrangle, the common room has a larger bay window. An abstract sculpture by Hubert Dalwood, from 1962, has been positioned on the lawn inside the college. Dalwood also designed the fountain in the pool in the upper quadrangle, although his plan for a spray of water was not implemented, "leaving the sculpture with no obvious purpose".
The hall has a floor of black and white marble and arches made of concrete supporting an oak roof with red panels. The furniture in the hall was designed by, and the chairs were built by, Edward Barnsley. Lord Nuffield's coat of arms are displayed over the fireplace, carved from a single piece of stone, and his portrait, painted by Sir Arthur Cope, hangs in the hall. The chapel, on the south side of the college, can seat forty people. It has five abstract stained glass windows that were designed by John Piper and executed by Patrick Reyntiens, and a metal reredos with a bronze crucifix. The roofs are finished with Collyweston stone slates from Northamptonshire. Many other Oxford colleges are roofed with Stonesfield stone slate from a quarry 10 miles (16 km) northwest of Oxford, but these were no longer available when Nuffield was built. The main building stone used is Clipsham stone. The tower, which has nine floors, is about 90 feet (27 m) tall, with the flèche taking the total height to about 150 feet (46 m). It was the first tower built in Oxford for 200 years. Work was carried out in the library in 1999 to extend the total shelf-length to just under 6 kilometres (3.7 mi). The library contains paintings of "Spring" and "Winter" by Derrick Greaves and "Summer" and "Autumn" by Edward Middleditch. 
Question: What has five abstract stained glass windows?
Output (English): The chapel.