Yesterday, my yoga and meditation practice took place by the river. Seated comfortably, I set my timer for 20 minutes, then took a nice long breath in, and opened my "ears". The following were the ambient sounds I noticed and focused on: the wind, birds singing, a boat's horn, a man calling out to his dog "Bernie", and the waves crashing on the shore after a containership sailed by. During that time, my mind did race occasionally, but there was always an ambient sound ready to take me back to my meditation.
If you are new to meditation, and wish to start a practice, you may refer to this article for a few helpful points. TIPS ON HOW TO START A MEDITATION PRACTICE
Wishing you happy meditation and if you can, take it outside!