The feature, that defines the quality of intervention, is the staircase tower added to the north wing to replace a previous security steel staircase.

一处彰显项目品味的部分是，将北侧原有的铁质安全楼梯改成了一处塔楼。

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The next is a tower with a staircase, elevator and water storage space.

其次是一座装着楼梯的高塔，留有安装电梯和蓄水池的空间；

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This main foyer staircase has a liberating and therapeutic effect from the two-storey glass tower next to it.

这个主要的大厅楼梯因为有这个它旁边两层玻璃塔而产生了一种释放感与治愈性。

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All that was left of the control tower after the crash was a buckled metal exterior staircase.

BBC: Italy deaths as Genoa ship hits control tower

The greatest testament to their research, though, may be at Versailles itself, where they've recently seen the complete restoration of a flying wooden staircase, collapsed since shortly after the Revolution, in Marie-Antoinette's Marlborough Tower.

FORBES: Palace Coup