my @cities = qw(Berlin Hamburg North_Adams);

my $htc = HTML::Template::Compiled->new(
    scalarref => \"<select><%html_option cities %></select>",
    plugin => [qw(::HTML_Tags)],
);
$htc->param(
    cities => [
        1, # selected
        map { [$_, $cities[$_]] } 0..$#cities],
);