Hertford in the context of "Hertford Castle"

The River Lea (/ˈliː/ LEE) is in the East of England and Greater London. It originates in Bedfordshire, in the Chiltern Hills, and flows southeast through Hertfordshire, along the Essex border and into Greater London, to meet the River Thames at Bow Creek. It is one of the largest rivers in London and the easternmost major tributary of the Thames.

The river's significance as a major east–west barrier and boundary has tended to obscure its importance as a north–south trade route. Below Hertford the river has since medieval times had alterations made to make it more navigable for boats between the Thames and eastern Hertfordshire and Essex, known as the Lee Navigation. This stimulated much industry along its banks. The navigable River Stort, the main tributary, joins it at Hoddesdon.

Baldock (/ˈbɔːldək/ BAWL-dək) is a historic market town in the North Hertfordshire district of Hertfordshire, England. The River Ivel rises from springs in the town. It lies 33 miles (53 km) north of London and 14 miles (23 km) north northwest of the county town of Hertford. Nearby towns include Royston to the northeast, Letchworth and Hitchin to the southwest and Stevenage to the south. In 2021 it had a population of 10,615.

Hitchin (/ˈhɪtʃɪn/) is a market town in the North Hertfordshire district of Hertfordshire, England. The town dates from at least the 7th century. It lies in the valley of the River Hiz at the north-eastern end of the Chiltern Hills. It is 16 miles (26 km) north-west of the county town of Hertford, and 35 miles (56 km) north of London. The population at the 2021 census was 35,220.

Hitchin grew around a market place and the adjoining parish church of St Mary on the western banks of the River Hiz. At the southern end of the town centre is Hitchin Priory, a former monastery dating back to 1317, which was partially rebuilt into a large country house with extensive parkland following the dissolution of the monasteries. The ancient parish of Hitchin covered a large rural area as well as the town itself, including several hamlets which subsequently became separate parishes, including Langley, Preston, St Ippolyts and Walsworth.

The West Anglia Main Line is one of the two main line railways that operate out of Liverpool Street (the other being the Great Eastern Main Line to Ipswich and Norwich). It runs generally north through Cheshunt, Broxbourne, Harlow, Bishop's Stortford and Audley End (near Saffron Walden) to Cambridge, with branches between serving Stratford, Hertford and Stansted Airport. The line runs along the boundary between Hertfordshire and Essex for much of its length.

In the early years, the line was the main route from London to Cambridge. Following the opening of the Cambridge Line between Hitchin and Cambridge, the West Anglia Main Line is now primarily a commuter route for stations between Cambridge and London. It was an important goods route for many years as the southern end of a route from coalfields in Yorkshire, and there are still freight trains which run occasionally to Harlow and Rye House Power Station, along with a Network Rail base at Broxbourne.