Hi,

the following example gives a hail of error messages, also neither the
verse nor the reference are typeset as part of the caption:

%%======================================================================
% !Mode:: "TeX:UK:UTF-8"
% !TEX program = XeLaTeX
% --------------------------------------------------------------------
\documentclass{scrartcl}

\usepackage{caption}%formating captions of floats
\usepackage{graphicx}%inclusion of images
\usepackage{url}%typeset internet links (preloaded in beamer)

\begin{document}

\urldef{\Fontana}\url
{https://upload.wikimedia.org/wikipedia/commons/3/32/Fontana_villa_borgh
ese.JPG}
\begin{figure}
\caption{The \textit{Fontana dei Cavalli Marini} in the garden of the
\textit{Villa Borghese} near Rome is an example for a dynamic
equilibrium. It inspired the Swiss poet \textsc{Conrad Ferdinand Meyer}
(1825--1898) to the well known poem ``Roman fountains'' (7th version of
1882):
\begin{verse}
Rising high and falling the jet \\
fills a bowl of marble, \\
which overflows, hidden in a mist, \\
and fills a second bowl; \\
the second gives, when it becomes to rich, \\
the water to a third: \\
and each takes and gives, \\
and flows and rests.
\end{verse}
The image was taken from \Fontana\ visited 2024-05-07.}
\label{fig:Fountains}
\centering
\includegraphics[width=\columnwidth]
{Graphics/Fontana_dei_Cavalli_Marini}
\end{figure}

\end{document}