留念(liú niàn) - to keep as a souvenir; as a keepsake in Mandarin

我wǒ们men在zài门mén口kǒu拍pāi照zhào留liú念niàn吧ba。

Let's take a photo by the door as a souvenir.

毕bì业yè那nà天tiān，全quán班bān同tóng学xué拍pāi照zhào留liú念niàn。

On graduation day the whole class took photos to remember it by.

这zhè本běn书shū送sòng给gěi你nǐ留liú念niàn。

Here's this book to remember me by.

他tā把bǎ车chē票piào留liú下xià来lái作zuò为wéi留liú念niàn。

He kept the ticket as a keepsake.

游yóu客kè们men在zài长cháng城chéng上shàng拍pāi照zhào留liú念niàn。

The tourists took photos on the Great Wall to remember their visit.