Question: Heaton Park BT Tower lies on the banks of the reservoir, which is close to Junction 18 of a motorway that encompasses which city ?

Context paragraphs:
Heaton Park tram stop: Heaton Park is a stop on the Bury Line of Greater Manchester's light rail Metrolink system.  The station is part of Ticketing Zone B, and is located at the corner of Whittaker Lane and Bury Old Road, with an entrance to Heaton Park.

Heaton Park Tramway: The Heaton Park Tramway is a heritage tramway running old trams as a visitor attraction in Heaton Park, Manchester.

Heaton Park BT Tower: Heaton Park BT Tower is a 238 foot (72.54 metres) tall telecommunication tower built of reinforced concrete close to the banks of Heaton Park Reservoir, at Heaton Park, Manchester, England.  Heaton Park BT Tower is one of the few British towers built of reinforced concrete, and one of seven BT towers of the 'Chilterns' design.

Wotton-under-Edge BT Tower: Wotton-under-Edge BT Tower is a 76.2 metres ( 250 ft) tall telecommunication tower built of reinforced concrete at Wotton-under-Edge in Gloucestershire, UK.  Wotton-under-Edge BT Tower is one of the few British towers built of reinforced concrete.

BT Tower: The BT Tower is a communications tower located in Fitzrovia, London, owned by BT Group.  It has been previously known as the GPO Tower, the Post Office Tower and the Telecom Tower.  The main structure is 177 m high, with a further section of aerial rigging bringing the total height to 191 m .  It should not be confused with the BT Centre (the global headquarters of BT).  Its Post Office code was YTOW.

Reunion Tour (The Stone Roses): The Reunion Tour was a rock concert tour by The Stone Roses.  Three homecoming shows in Heaton Park, Manchester and a show in Phoenix Park, Dublin were the first shows to be announced by the band.  Fifty shows eventually took place in Europe, Asia, North America and Oceania.  The Heaton Park shows currently hold the record for the fastest selling rock gigs in UK history.  The "Irish Independent" described the Dublin leg of the tour as "one of the most anticipated gigs of the year."  The Stone Roses have also re-entered the music charts on the back of the tour.

Tolsford Hill BT Tower: Tolsford Hill BT Tower is a telecommunication tower built of reinforced concrete at Tolsford Hill on the North Downs near Folkestone, Kent.  Tolsford Hill BT Tower is one of the few British towers built of reinforced concrete and is 67.36 metres ( 221 ft) high.

Heaton Park Reservoir: Heaton Park Reservoir is a granite sided reservoir in the North-West of England, on the border between the City of Manchester and Bury and is owned by United Utilities, and can be found within the grounds of Heaton Park.  Heaton Park BT Tower lies on the banks of the reservoir, which is close to Junction 18 of the M60 motorway.

M60 motorway: The M60 motorway, Manchester Ring Motorway, or Manchester Outer Ring Road, is an orbital motorway in Greater Manchester, a metropolitan county in North West England.  Built over a 40-year period, it passes through all Greater Manchester's metropolitan boroughs except for Wigan and Bolton.  Most of the City of Manchester is encompassed within the motorway, except for the southernmost part of the city (primarily the Wythenshawe area and Manchester Airport), which are served by the M56.

Sutton Common BT Tower: Sutton Common BT Tower is a 72-metre (238-foot) radio tower built of reinforced concrete at Macclesfield, Cheshire, England.  It is one of the few communication towers in the United Kingdom built of reinforced concrete and relays signals to Heaton Park in the north and Pye Green to the south.

Supporting paragraphs: Heaton Park Reservoir M60 motorway
Answer: Manchester