Too Large to See All

The world is a very varied place,
And most would agree it is the case
That none can possibly see it all
However long and far they trawl.
Just a continent is too much
For anyone to more than touch
A few of the things existing there,
Even if it's largely bare.
And when it's large and stretches far,
Its very size will tend to bar
The likelihood  they can explore
More than a bit of it before
Old age will finally descend
With working life brought to an end.
For every bit of land enshrines
A history that enquiring minds
Will almost surely want to climb
If only they can find the time.
And then there are the towns as well,
The places where the people dwell;
Each could involve a life-time's toil,
Excluding all the country soil.