Musing as an adjective is defined as “absorbed in thought; meditative” and as a noun it is defined as “contemplation; reflection”*.
The city of Prague has very good public transportation system (http://www.dpp.cz/en/) with both an efficient metro and extensive above ground tramway system. I prefer to take a tram whenever possible because of the opportunity to observe and muse on one’s journey.
Observing the surroundings in a city such as Prague is continuing source of pleasure and wonder for me.
The surroundings, the architecture and the rhythmic movement of the trams are very conducive to musing. Feelings of contemplation, meditation and reflection seem very natural.
* definitions from www.dictionary.com