There are some places where you feel a sudden and overpowering sense of evil. The site of an infamous event is likely to generate such feelings. By any standard the death of Jan Masaryk, foreign minister of what was then Czechoslovakia was a notorious occurrence.
After the post-war coup which inaugurated the era of Soviet-style communism in his country, Masaryk still remained a member of the government. His presence was an obstruction to the implementation of the new system. On March 10th, 1948, he either fell or was pushed from the bathroom window of his private apartment in the Foreign Ministry and died on the mosaic paving of the courtyard 40 feet below.
On a visit to the Foreign Ministry this week I saw the window from which Jan Masaryk departed this world. The spot where he hit the ground is marked by a marble plaque engraved with his name, the date of his death and a simple cross.
It brought home the lesson that one should never take democracy for granted, least of all in this central European land which was occupied in turn by the Germans and the Russians in the last century.
Czechoslovakia is now two states, Slovakia and the Czech Republic, and I was on my way to meet the man who is leading the Czech negotiations for accession to the EU, Mr Pavel Telicka. Young and eager - he was born in 1965 - the Minister for European Affairs had agreed to talk to me about the way negotiations were progressing.
He expressed his anxiety that the Irish people should do what he clearly regarded as the decent thing on June 7th by voting Yes to the Treaty of Nice. "If there would be a No to ratification in any member-state - and Ireland is the only one having a referendum probably - it would have serious implications for the enlargement process.
"It would not kill it once and for all but it would cause serious difficulties which would lead to considerable delays, so I would very much appreciate if the Irish citizens while voting on the Nice Treaty would realise that they are also voting on the future accession of the candidate countries," he said.
Their country had its "velvet revolution" in 1989 when it got rid of Soviet communism and instituted a new democratic era but there is surprise in some quarters that the Czechs still have not been admitted to the EU. As far as Mr Telicka is concerned, there is little reason for further delay: "We are well on target to finish the negotiations if there would be sufficient political will on the EU side to sign the Treaty on accession sometime next year."
Like a lot of Czechs he is disturbed by the moves to restrict free movement of labour from the accession countries to the rest of the EU.
Germany and Austria in particular have sought a transition period for fear their labour markets will be flooded with immigrant workers from the new and hungry member-states. He insists it is not the case that large numbers of Czechs want to emigrate to Germany: workers will not move even within the country, much less outside it.
It is a sensitive issue with the Czech electorate as foreign travel was very severely restricted in communist times. "It's psychological and people ask me, `Will we really be a part of Europe, Will we have the same rights', and I say, `Yes you will be citizens of the European Union'. And they say: `But why are there to be limits on free movement of workers?' "
I point out that the possible security implications of the Nice Treaty are a key topic in the Irish referendum debate. It does not appear to be an issue in the Czech Republic which even joined the North Atlantic Treaty Organisation (NATO) two years ago. "We are believers in the US presence in Europe," Mr Telicka says. "We have a history which says that Europe can hardly do without an American presence."
Czechs who favour membership of the EU are not slow to point out that Prague is located to the west of Vienna and that it is not a case of joining but rejoining the European mainstream from which they have been excluded since the Munich Agreement of 1938 which opened the way to Nazi domination and subsequent isolation behind the Iron Curtain.
The governing Social Democrats have a more "Europhile" position than, say, the former Prime Minister, Mr Vaclav Klaus, who warned recently that the existing EU member-states regarded Czech accession not as the return of a lost son but as the adoption of a child they knew very little about.
There are elements in Czech politics who would favour staying out of the EU and forging an alternative destiny for their country. So for many different reasons, a lot of people in the Czech Republic will be keeping their fingers crossed when Irish votes are being counted after June 7th.