I just like to give you some background on how the Dutch make their living.
Holland has one of the highest population densities in the world. So it may surprise you that agriculture is still an important source of income. Of course you heard about the famous Dutch tulips. They are not grown for tourist purposes, but it is hard selling business. In many parts of the country you may see the glass greenhouses where Dutch farmers grow fruits and vegetables. You will recognize the large choice in Dutch shops. In the countryside you may smell our large porc farms. A single farm housing 1000 pigs is no exception. The same holds for chickens and cows. You also may notice a large industry based on the agriculture. In Wageningen we have the agricultural University, which is one of the best in the world, causing people to speak of "Food Valley" similar to Silicon Valley in California. Large companies are Unilever, Nutricia (now owned by Nestlé), Friesland food etcetera.
In the sixties we found a very large source of natural gaz under Dutch bottom. It is an important source of prosperity for the Dutch. Our agriculture would not exist at this scale without this source.
We have some charcoal, but it is not economic to exploit the Dutch mines. As remainder of former mine industry, we still have a large chemical industry with DSM and Shell as leading companies.
In Twente, near Hengelo we find salt in the bottom. This resource also created a chemical industry (Akzo-Nobel).
Smaller resources are chalk and fine clay.
Transportation is major Dutch business. It is strongly connected with the water. Rotterdam is the second large harbour in the world, serving mainly the German industries. We have a very good infrastructure, which is an aspect of the country you may not like too much during hiking.
Trade and banking
Originating in the 17th century (our golden age), the Dutch have a long tradition in trade. Combined with transportation and agriculture this is the core of our business. Of course banking is related to the trading business very closely. One of the advantages we have is that many languages are spoken. Nearly all Dutch speak English quite well. because of immigration, you can find people from all over the world living in Holland.
We used to have large industries, but due to the increasing prosperity most of them moved their production to other countries.