to pass below. A temporary diversion of the canal was put in place to allow construction of the aqueduct and the entrances to the diversion remain visible. A feeder from the River Tanat enters the canal above Carreghofa Locks. Built in 1822 by the Montgomeryshire Canal Company, it originally fed water between the locks so that none could enter the Ellesmere Canal. When the canals were united, the feeder was diverted to enter the canal above the locks so that the lowest pound of the former Ellesmere Canal also gained from the feeder. The end of the Llanymynech Branch of the Ellesmere Canal joins end-on to the Eastern Branch of the Montgomeryshire Canal at Carreghofa Locks. Eastern Branch The section of the canal from Carreghofa to Arddleen is in water although several bridges have been lowered. Between the two Carreghofa Locks was a side pond. This was necessary as the pound between the locks is short. Near the Vyrnwy Aqueduct, arches were built in the embankment of the canal to provide protection from flooding of the River Vyrnwy. The aqueduct itself has been repaired and strengthened in the 1820s, 1890s and 1970s. It sometimes can be seen to leak into the River Vyrnwy though the leaks self-heal. Unlike the nearby Chirk Aqueduct and Pontcysyllte Aqueduct, which have cast iron troughs, the Vyrnwy Aqueduct is built of stone and is puddled. The weight of this structure led to it being strengthened with tie bars and girders in the 1820s. Bridges 102 and 103 carry a major road and have been lowered since the canal was closed. To restore navigation, lowering of the pound by addition of an extra lock has been proposed. The section of the canal from Arddleen to Refail (Efail-Fach) Bridge is navigable. The Guilsfield Arm never actually reached Guilsfield. The arm was long with a wharf at its terminus. It was level, with no locks or tunnels, and this was achieved by a cutting 600 feet long and up to 20 feet deep. Today the arm is cut off from the main line by a lowered bridge. A short section has been made into a nature reserve and beyond that, the arm is dry. The pound below Burgedin Bottom Lock is the sump pound of the canal, the Eastern Branch of the Montgomeryshire being filled by lockings from the Ellesmere, the Tanat feeder at Carreghofa and a feeder