A northern extension to 110th Street was added in 1859.

Work continued on the rest of the northern extension.

It is part of the northern extension of that line.

The northern extension was built later to house rail services.

By 1879 the tower and the northern extension from it had been built.

However, this northern extension was reversed by the following year.

In December 2010, three stations on the northern extension of the line opens.

In June 2011, two more stations on the northern extension of the line opens.

Most of the groundwork for the northern extension was put in place around this time.

On 7 September 2006 the third and final phase of the northern extension opened.