A small number of medieval buildings remain standing in the town.
St Denys' Church and St Botolph's in Quarrington date to the 12th and 13th centuries respectively, while Sleaford's half-timbered vicarage is 15th-century.
St Denys' Church is noted for its tracery and its stone broach spire is one of the oldest in England.
Cogglesford Mill is the only remaining watermill in town and is a testament to the economic importance of the River Slea from the late-Saxon period onwards.
The Bishops of Lincoln used the medieval town as a base, constructing the now-ruined Sleaford Castle, and as a means of extracting produce and wealth through demesne farming and by granting a market and limited freedoms to the town.
As a result, the oldest areas are the market place and the four roads which meet there: Northgate, Southgate, Eastgate and Westgate; many 18th- and 19th-century buildings are found in this area.

Buildings dating from these centuries include William Alvey's baroque house on Northgate, the Manor House on Northgate inset with medieval masonry, and Sessions House on the Market Place.
The Carre family founded the grammar school which was rebuilt in 1834, the hospital, rebuilt in 1830, and the almshouses, rebuilt 1857, while the Victorian builders Charles Kirk and Thomas Parry constructed or added to numerous public buildings and private residences, including Lafford Terrace and their own houses on Southgate and at Westholme.

During the Industrial Revolution, the Slea was canalised in 1794 and the Sleaford Navigation Company constructed offices and wharves along Carre Street.
The canal brought trade, while the Gothic-fronted gasworks on Eastgate lit the town from 1839.
Benjamin Handley and Anthony Peacock financed and benefited from the navigation and founded the bank that took over Alvey's House on Northgate and later added a Baroque extension; Henry Handley, a Member of Parliament, is commemorated by the Handley Memorial on Southgate, a Gothic monument in the style of an Eleanor Cross.
During the 1850s, the railways arrived and the station was built in a Gothic style.
Sleaford's agricultural location and its new transport links encouraged seed trading and malting in the late 19th century: the seed merchant Charles Sharpe's house, The Pines, is on Boston Road.
The massive Bass and Company maltings complex, constructed in brick off Mareham Lane between 1892 and 1905, is grade II* listed and has a frontage more than 1,000 feet long.
A small number of medieval buildings remain standing in the town. St Denys' Church and St Botolph's in Quarrington date to the 12th and 13th centuries respectively, while Sleaford's half-timbered vicarage is 15th-century. St Denys' Church is noted for its tracery and its stone broach spire is one of the oldest in England. Cogglesford Mill is the only remaining watermill in town and is a testament to the economic importance of the River Slea from the late-Saxon period onwards. The Bishops of Lincoln used the medieval town as a base, constructing the now-ruined Sleaford Castle, and as a means of extracting produce and wealth through demesne farming and by granting a market and limited freedoms to the town. As a result, the oldest areas are the market place and the four roads which meet there: Northgate, Southgate, Eastgate and Westgate; many 18th- and 19th-century buildings are found in this area.
Buildings dating from these centuries include William Alvey's baroque house on Northgate, the Manor House on Northgate inset with medieval masonry, and Sessions House on the Market Place. The Carre family founded the grammar school which was rebuilt in 1834, the hospital, rebuilt in 1830, and the almshouses, rebuilt 1857, while the Victorian builders Charles Kirk and Thomas Parry constructed or added to numerous public buildings and private residences, including Lafford Terrace and their own houses on Southgate and at Westholme.
During the Industrial Revolution, the Slea was canalised in 1794 and the Sleaford Navigation Company constructed offices and wharves along Carre Street. The canal brought trade, while the Gothic-fronted gasworks on Eastgate lit the town from 1839. Benjamin Handley and Anthony Peacock financed and benefited from the navigation and founded the bank that took over Alvey's House on Northgate and later added a Baroque extension; Henry Handley, a Member of Parliament, is commemorated by the Handley Memorial on Southgate, a Gothic monument in the style of an Eleanor Cross. During the 1850s, the railways arrived and the station was built in a Gothic style. Sleaford's agricultural location and its new transport links encouraged seed trading and malting in the late 19th century: the seed merchant Charles Sharpe's house, The Pines, is on Boston Road. The massive Bass and Company maltings complex, constructed in brick off Mareham Lane between 1892 and 1905, is grade II* listed and has a frontage more than 1,000 feet long.
Sleaford