The Low Level station did not last long after the 1921 Railways Act, and closed in 1931 (though the line continued to serve Nantgarw Colliery until the late 1980s.

[4] The sinking of the twin shafts in 1911 reached the coal seam at a depth of more than 850 yards in 1915, placing them 2000 ft below sea level and making Nantgarw the deepest pit to be sunk in the South Wales Coalfield up to that time.

[1][5][6] Having suffered from various geographical issues, Powell Duffryn designed a development scheme in 1937, but work was suspended when World War II broke out in 1939.

[4] In 1982 output declined steeply as a major coal seam at Windsor became unworkable, while in 1984 an overtime ban led directly to the 1984/5 UK miners strike spreading to South Wales.

After the closure of the Nantgarw/Windsor Colliery and Coking works 18 months after the miners' strike, the site was developed as Parc Nantgarw, joined to the larger Trefforest Industrial Estate.

All that now remains of Nantgarw colliery are two small concrete pyramids marking the sites of the two shafts and a commemorative winding wheel.

[7] Parc Nantgarw is home to the headquarters of Cadw (the Welsh equivalent of English Heritage), and a large office for the newly relocated Santia Consulting.

GE Aviation Wales, located on the Caerphilly Road, employs about 1500 people in the testing, repair and maintenance of aircraft engines, including GE90, GP7200, CFM56 and RB211.