Stunning Views and a Prime Location

I was walking through the fields one day when I heard a huffing and puffing growing closer and closer, like someone had been running so hard they could barely catch their breath.
"Hello?" I called out, although I couldn't see anyone.  "Are you alright?"
The sound stopped but a few paces from me.  I was curious, and a little concerned now I couldn't hear the breath - what if the fellow had fainted or worse?  I made my way forward through the long grass towards the hedge, when:
"Ooof!"
I had stepped into someone, although I couldn't see them!
"Mind where you're going!" a voice cried out angrily.
"I... I can't see you!" I replied, more puzzled than afraid now.
All of a sudden a troll popped into view.  He was no higher than my waist, with a big nose and horns and massive feet, one of which he was hopping on, whilst rubbing the other. (Apparently I had stepped on it.)
"Oh my!" I exclaimed.  "I'm terribly sorry."
"Yes well, you humans are always tromping everywhere.  Stomp stomp, over my bridge, over my foot!" he mumbled crossly.
"I thought that was goats..." I ventured.
"Goats?  Why would goats build bridges?" he frowned.  "Anyway, I must hurry, I have a long way to go."
"Back to your bridge?"
"No, I'm moving."  He scooped up a stick, on the end of which was a loaded knotted hankerchief, and slung it over his shoulder.  "I want to upgrade - bigger bridge, quieter location."  He pointed behind me.
I turned and followed his point.
"I can't see a bridge.  I'm not even sure there are any rivers near here..."
"I'm not going for a river bridge.  I'm going to live under that bridge."
I looked again, and realised he was pointing into the sky.  A rainbow arced across a stormy grey, its colours bright and strong in the sunlight.
"The rainbow?"
"Yes.  But I have to hurry if I'm going to catch it.  Mind where you walk in future!"
And with that he was off again, flapping those big feet and huffing and puffing his way across the field, chasing the rainbow.  I often wonder now if the little troll made it to his new bridge, or if he's still running about trying to catch up with it.  Still, there are worse things to do than chase rainbows.